feat(skills): add engineering skill definitions under common/engineering/ all from @mattpocock

Add 10 skill definitions covering codebase design, domain modeling,
test-driven development, triage, and development workflows:

- codebase-design: vocabulary and patterns for designing deep modules
- domain-modeling: build and sharpen project domain models
- grill-with-docs: interview-based design refinement with documentation
- improve-codebase-architecture: scan and report on deepening opportunities
- resolving-merge-conflicts: structured approach to merge/rebase conflicts
- setup-skills: per-repo configuration for engineering skills
- tdd: test-driven development workflow with vertical slices
- to-issues: break plans into tracer-bullet vertical slice issues
- to-prd: synthesize conversations into PRDs
- triage: state machine for issue/PR triage roles

Includes supporting files for ADR formats, issue tracker integrations
(GitHub, GitLab, Gitea), triage labels, and agent brief templates.

common/engineering/codebase-design/DEEPENING.md

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+# Deepening
+
+How to deepen a cluster of shallow modules safely, given its dependencies. Assumes the vocabulary in [SKILL.md](SKILL.md) — **module**, **interface**, **seam**, **adapter**.
+
+## Dependency categories
+
+When assessing a candidate for deepening, classify its dependencies. The category determines how the deepened module is tested across its seam.
+
+### 1. In-process
+
+Pure computation, in-memory state, no I/O. Always deepenable — merge the modules and test through the new interface directly. No adapter needed.
+
+### 2. Local-substitutable
+
+Dependencies that have local test stand-ins (PGLite for Postgres, in-memory filesystem). Deepenable if the stand-in exists. The deepened module is tested with the stand-in running in the test suite. The seam is internal; no port at the module's external interface.
+
+### 3. Remote but owned (Ports & Adapters)
+
+Your own services across a network boundary (microservices, internal APIs). Define a **port** (interface) at the seam. The deep module owns the logic; the transport is injected as an **adapter**. Tests use an in-memory adapter. Production uses an HTTP/gRPC/queue adapter.
+
+Recommendation shape: *"Define a port at the seam, implement an HTTP adapter for production and an in-memory adapter for testing, so the logic sits in one deep module even though it's deployed across a network."*
+
+### 4. True external (Mock)
+
+Third-party services (Stripe, Twilio, etc.) you don't control. The deepened module takes the external dependency as an injected port; tests provide a mock adapter.
+
+## Seam discipline
+
+- **One adapter means a hypothetical seam. Two adapters means a real one.** Don't introduce a port unless at least two adapters are justified (typically production + test). A single-adapter seam is just indirection.
+- **Internal seams vs external seams.** A deep module can have internal seams (private to its implementation, used by its own tests) as well as the external seam at its interface. Don't expose internal seams through the interface just because tests use them.
+
+## Testing strategy: replace, don't layer
+
+- Old unit tests on shallow modules become waste once tests at the deepened module's interface exist — delete them.
+- Write new tests at the deepened module's interface. The **interface is the test surface**.
+- Tests assert on observable outcomes through the interface, not internal state.
+- Tests should survive internal refactors — they describe behaviour, not implementation. If a test has to change when the implementation changes, it's testing past the interface.

common/engineering/codebase-design/DESIGN-IT-TWICE.md

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+# Design It Twice
+
+When the user wants to explore alternative interfaces for a chosen deepening candidate, use this parallel sub-agent pattern. Based on "Design It Twice" (Ousterhout) — your first idea is unlikely to be the best.
+
+Uses the vocabulary in [SKILL.md](SKILL.md) — **module**, **interface**, **seam**, **adapter**, **leverage**.
+
+## Process
+
+### 1. Frame the problem space
+
+Before spawning sub-agents, write a user-facing explanation of the problem space for the chosen candidate:
+
+- The constraints any new interface would need to satisfy
+- The dependencies it would rely on, and which category they fall into (see [DEEPENING.md](DEEPENING.md))
+- A rough illustrative code sketch to ground the constraints — not a proposal, just a way to make the constraints concrete
+
+Show this to the user, then immediately proceed to Step 2. The user reads and thinks while the sub-agents work in parallel.
+
+### 2. Spawn sub-agents
+
+Spawn 3+ sub-agents in parallel using the Agent tool. Each must produce a **radically different** interface for the deepened module.
+
+Prompt each sub-agent with a separate technical brief (file paths, coupling details, dependency category from [DEEPENING.md](DEEPENING.md), what sits behind the seam). The brief is independent of the user-facing problem-space explanation in Step 1. Give each agent a different design constraint:
+
+- Agent 1: "Minimize the interface — aim for 1–3 entry points max. Maximise leverage per entry point."
+- Agent 2: "Maximise flexibility — support many use cases and extension."
+- Agent 3: "Optimise for the most common caller — make the default case trivial."
+- Agent 4 (if applicable): "Design around ports & adapters for cross-seam dependencies."
+
+Include both [SKILL.md](SKILL.md) vocabulary and CONTEXT.md vocabulary in the brief so each sub-agent names things consistently with the architecture language and the project's domain language.
+
+Each sub-agent outputs:
+
+1. Interface (types, methods, params — plus invariants, ordering, error modes)
+2. Usage example showing how callers use it
+3. What the implementation hides behind the seam
+4. Dependency strategy and adapters (see [DEEPENING.md](DEEPENING.md))
+5. Trade-offs — where leverage is high, where it's thin
+
+### 3. Present and compare
+
+Present designs sequentially so the user can absorb each one, then compare them in prose. Contrast by **depth** (leverage at the interface), **locality** (where change concentrates), and **seam placement**.
+
+After comparing, give your own recommendation: which design you think is strongest and why. If elements from different designs would combine well, propose a hybrid. Be opinionated — the user wants a strong read, not a menu.

common/engineering/codebase-design/SKILL.md

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+---
+name: codebase-design
+description: Shared vocabulary for designing deep modules. Use when the user wants to design or improve a module's interface, find deepening opportunities, decide where a seam goes, make code more testable or AI-navigable, or when another skill needs the deep-module vocabulary.
+---
+
+# Codebase Design
+
+Design **deep modules**: a lot of behaviour behind a small interface, placed at a clean seam, testable through that interface. Use this language and these principles wherever code is being designed or restructured. The aim is leverage for callers, locality for maintainers, and testability for everyone.
+
+## Glossary
+
+Use these terms exactly — don't substitute "component," "service," "API," or "boundary." Consistent language is the whole point.
+
+**Module** — anything with an interface and an implementation. Deliberately scale-agnostic: a function, class, package, or tier-spanning slice. _Avoid_: unit, component, service.
+
+**Interface** — everything a caller must know to use the module correctly: the type signature, but also invariants, ordering constraints, error modes, required configuration, and performance characteristics. _Avoid_: API, signature (too narrow — they refer only to the type-level surface).
+
+**Implementation** — what's inside a module, its body of code. Distinct from **Adapter**: a thing can be a small adapter with a large implementation (a Postgres repo) or a large adapter with a small implementation (an in-memory fake). Reach for "adapter" when the seam is the topic; "implementation" otherwise.
+
+**Depth** — leverage at the interface: the amount of behaviour a caller (or test) can exercise per unit of interface they have to learn. A module is **deep** when a large amount of behaviour sits behind a small interface, **shallow** when the interface is nearly as complex as the implementation.
+
+**Seam** _(Michael Feathers)_ — a place where you can alter behaviour without editing in that place; the *location* at which a module's interface lives. Where to put the seam is its own design decision, distinct from what goes behind it. _Avoid_: boundary (overloaded with DDD's bounded context).
+
+**Adapter** — a concrete thing that satisfies an interface at a seam. Describes *role* (what slot it fills), not substance (what's inside).
+
+**Leverage** — what callers get from depth: more capability per unit of interface they learn. One implementation pays back across N call sites and M tests.
+
+**Locality** — what maintainers get from depth: change, bugs, knowledge, and verification concentrate in one place rather than spreading across callers. Fix once, fixed everywhere.
+
+## Deep vs shallow
+
+**Deep module** = small interface + lots of implementation:
+
+```
+┌─────────────────────┐
+│   Small Interface   │  ← Few methods, simple params
+├─────────────────────┤
+│                     │
+│  Deep Implementation│  ← Complex logic hidden
+│                     │
+└─────────────────────┘
+```
+
+**Shallow module** = large interface + little implementation (avoid):
+
+```
+┌─────────────────────────────────┐
+│       Large Interface           │  ← Many methods, complex params
+├─────────────────────────────────┤
+│  Thin Implementation            │  ← Just passes through
+└─────────────────────────────────┘
+```
+
+When designing an interface, ask:
+
+- Can I reduce the number of methods?
+- Can I simplify the parameters?
+- Can I hide more complexity inside?
+
+## Principles
+
+- **Depth is a property of the interface, not the implementation.** A deep module can be internally composed of small, mockable, swappable parts — they just aren't part of the interface. A module can have **internal seams** (private to its implementation, used by its own tests) as well as the **external seam** at its interface.
+- **The deletion test.** Imagine deleting the module. If complexity vanishes, it was a pass-through. If complexity reappears across N callers, it was earning its keep.
+- **The interface is the test surface.** Callers and tests cross the same seam. If you want to test *past* the interface, the module is probably the wrong shape.
+- **One adapter means a hypothetical seam. Two adapters means a real one.** Don't introduce a seam unless something actually varies across it.
+
+## Designing for testability
+
+Good interfaces make testing natural:
+
+1. **Accept dependencies, don't create them.**
+
+   ```typescript
+   // Testable
+   function processOrder(order, paymentGateway) {}
+
+   // Hard to test
+   function processOrder(order) {
+     const gateway = new StripeGateway();
+   }
+   ```
+
+2. **Return results, don't produce side effects.**
+
+   ```typescript
+   // Testable
+   function calculateDiscount(cart): Discount {}
+
+   // Hard to test
+   function applyDiscount(cart): void {
+     cart.total -= discount;
+   }
+   ```
+
+3. **Small surface area.** Fewer methods = fewer tests needed. Fewer params = simpler test setup.
+
+## Relationships
+
+- A **Module** has exactly one **Interface** (the surface it presents to callers and tests).
+- **Depth** is a property of a **Module**, measured against its **Interface**.
+- A **Seam** is where a **Module**'s **Interface** lives.
+- An **Adapter** sits at a **Seam** and satisfies the **Interface**.
+- **Depth** produces **Leverage** for callers and **Locality** for maintainers.
+
+## Rejected framings
+
+- **Depth as ratio of implementation-lines to interface-lines** (Ousterhout): rewards padding the implementation. We use depth-as-leverage instead.
+- **"Interface" as the TypeScript `interface` keyword or a class's public methods**: too narrow — interface here includes every fact a caller must know.
+- **"Boundary"**: overloaded with DDD's bounded context. Say **seam** or **interface**.
+
+## Going deeper
+
+- **Deepening a cluster given its dependencies** — see [DEEPENING.md](DEEPENING.md): dependency categories, seam discipline, and replace-don't-layer testing.
+- **Exploring alternative interfaces** — see [DESIGN-IT-TWICE.md](DESIGN-IT-TWICE.md): spin up parallel sub-agents to design the interface several radically different ways, then compare on depth, locality, and seam placement.

common/engineering/domain-modeling/ADR-FORMAT.md

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+# ADR Format
+
+ADRs live in `docs/adr/` and use sequential numbering: `0001-slug.md`, `0002-slug.md`, etc.
+
+Create the `docs/adr/` directory lazily — only when the first ADR is needed.
+
+## Template
+
+```md
+# {Short title of the decision}
+
+{1-3 sentences: what's the context, what did we decide, and why.}
+```
+
+That's it. An ADR can be a single paragraph. The value is in recording *that* a decision was made and *why* — not in filling out sections.
+
+## Optional sections
+
+Only include these when they add genuine value. Most ADRs won't need them.
+
+- **Status** frontmatter (`proposed | accepted | deprecated | superseded by ADR-NNNN`) — useful when decisions are revisited
+- **Considered Options** — only when the rejected alternatives are worth remembering
+- **Consequences** — only when non-obvious downstream effects need to be called out
+
+## Numbering
+
+Scan `docs/adr/` for the highest existing number and increment by one.
+
+## When to offer an ADR
+
+All three of these must be true:
+
+1. **Hard to reverse** — the cost of changing your mind later is meaningful
+2. **Surprising without context** — a future reader will look at the code and wonder "why on earth did they do it this way?"
+3. **The result of a real trade-off** — there were genuine alternatives and you picked one for specific reasons
+
+If a decision is easy to reverse, skip it — you'll just reverse it. If it's not surprising, nobody will wonder why. If there was no real alternative, there's nothing to record beyond "we did the obvious thing."
+
+### What qualifies
+
+- **Architectural shape.** "We're using a monorepo." "The write model is event-sourced, the read model is projected into Postgres."
+- **Integration patterns between contexts.** "Ordering and Billing communicate via domain events, not synchronous HTTP."
+- **Technology choices that carry lock-in.** Database, message bus, auth provider, deployment target. Not every library — just the ones that would take a quarter to swap out.
+- **Boundary and scope decisions.** "Customer data is owned by the Customer context; other contexts reference it by ID only." The explicit no-s are as valuable as the yes-s.
+- **Deliberate deviations from the obvious path.** "We're using manual SQL instead of an ORM because X." Anything where a reasonable reader would assume the opposite. These stop the next engineer from "fixing" something that was deliberate.
+- **Constraints not visible in the code.** "We can't use AWS because of compliance requirements." "Response times must be under 200ms because of the partner API contract."
+- **Rejected alternatives when the rejection is non-obvious.** If you considered GraphQL and picked REST for subtle reasons, record it — otherwise someone will suggest GraphQL again in six months.

common/engineering/domain-modeling/CONTEXT-FORMAT.md

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+# CONTEXT.md Format
+
+## Structure
+
+```md
+# {Context Name}
+
+{One or two sentence description of what this context is and why it exists.}
+
+## Language
+
+**Order**:
+{A one or two sentence description of the term}
+_Avoid_: Purchase, transaction
+
+**Invoice**:
+A request for payment sent to a customer after delivery.
+_Avoid_: Bill, payment request
+
+**Customer**:
+A person or organization that places orders.
+_Avoid_: Client, buyer, account
+```
+
+## Rules
+
+- **Be opinionated.** When multiple words exist for the same concept, pick the best one and list the others under `_Avoid_`.
+- **Keep definitions tight.** One or two sentences max. Define what it IS, not what it does.
+- **Only include terms specific to this project's context.** General programming concepts (timeouts, error types, utility patterns) don't belong even if the project uses them extensively. Before adding a term, ask: is this a concept unique to this context, or a general programming concept? Only the former belongs.
+- **Group terms under subheadings** when natural clusters emerge. If all terms belong to a single cohesive area, a flat list is fine.
+
+## Single vs multi-context repos
+
+**Single context (most repos):** One `CONTEXT.md` at the repo root.
+
+**Multiple contexts:** A `CONTEXT-MAP.md` at the repo root lists the contexts, where they live, and how they relate to each other:
+
+```md
+# Context Map
+
+## Contexts
+
+- [Ordering](./src/ordering/CONTEXT.md) — receives and tracks customer orders
+- [Billing](./src/billing/CONTEXT.md) — generates invoices and processes payments
+- [Fulfillment](./src/fulfillment/CONTEXT.md) — manages warehouse picking and shipping
+
+## Relationships
+
+- **Ordering → Fulfillment**: Ordering emits `OrderPlaced` events; Fulfillment consumes them to start picking
+- **Fulfillment → Billing**: Fulfillment emits `ShipmentDispatched` events; Billing consumes them to generate invoices
+- **Ordering ↔ Billing**: Shared types for `CustomerId` and `Money`
+```
+
+The skill infers which structure applies:
+
+- If `CONTEXT-MAP.md` exists, read it to find contexts
+- If only a root `CONTEXT.md` exists, single context
+- If neither exists, create a root `CONTEXT.md` lazily when the first term is resolved
+
+When multiple contexts exist, infer which one the current topic relates to. If unclear, ask.

common/engineering/domain-modeling/SKILL.md

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+---
+name: domain-modeling
+description: Build and sharpen a project's domain model. Use when the user wants to pin down domain terminology or a ubiquitous language, record an architectural decision, or when another skill needs to maintain the domain model.
+---
+
+# Domain Modeling
+
+Actively build and sharpen the project's domain model as you design. This is the *active* discipline — challenging terms, inventing edge-case scenarios, and writing the glossary and decisions down the moment they crystallise. (Merely *reading* `CONTEXT.md` for vocabulary is not this skill — that's a one-line habit any skill can do. This skill is for when you're changing the model, not just consuming it.)
+
+## File structure
+
+Most repos have a single context:
+
+```
+/
+├── CONTEXT.md
+├── docs/
+│   └── adr/
+│       ├── 0001-event-sourced-orders.md
+│       └── 0002-postgres-for-write-model.md
+└── src/
+```
+
+If a `CONTEXT-MAP.md` exists at the root, the repo has multiple contexts. The map points to where each one lives:
+
+```
+/
+├── CONTEXT-MAP.md
+├── docs/
+│   └── adr/                          ← system-wide decisions
+├── src/
+│   ├── ordering/
+│   │   ├── CONTEXT.md
+│   │   └── docs/adr/                 ← context-specific decisions
+│   └── billing/
+│       ├── CONTEXT.md
+│       └── docs/adr/
+```
+
+Create files lazily — only when you have something to write. If no `CONTEXT.md` exists, create one when the first term is resolved. If no `docs/adr/` exists, create it when the first ADR is needed.
+
+## During the session
+
+### Challenge against the glossary
+
+When the user uses a term that conflicts with the existing language in `CONTEXT.md`, call it out immediately. "Your glossary defines 'cancellation' as X, but you seem to mean Y — which is it?"
+
+### Sharpen fuzzy language
+
+When the user uses vague or overloaded terms, propose a precise canonical term. "You're saying 'account' — do you mean the Customer or the User? Those are different things."
+
+### Discuss concrete scenarios
+
+When domain relationships are being discussed, stress-test them with specific scenarios. Invent scenarios that probe edge cases and force the user to be precise about the boundaries between concepts.
+
+### Cross-reference with code
+
+When the user states how something works, check whether the code agrees. If you find a contradiction, surface it: "Your code cancels entire Orders, but you just said partial cancellation is possible — which is right?"
+
+### Update CONTEXT.md inline
+
+When a term is resolved, update `CONTEXT.md` right there. Don't batch these up — capture them as they happen. Use the format in [CONTEXT-FORMAT.md](./CONTEXT-FORMAT.md).
+
+`CONTEXT.md` should be totally devoid of implementation details. Do not treat `CONTEXT.md` as a spec, a scratch pad, or a repository for implementation decisions. It is a glossary and nothing else.
+
+### Offer ADRs sparingly
+
+Only offer to create an ADR when all three are true:
+
+1. **Hard to reverse** — the cost of changing your mind later is meaningful
+2. **Surprising without context** — a future reader will wonder "why did they do it this way?"
+3. **The result of a real trade-off** — there were genuine alternatives and you picked one for specific reasons
+
+If any of the three is missing, skip the ADR. Use the format in [ADR-FORMAT.md](./ADR-FORMAT.md).

common/engineering/grill-with-docs/SKILL.md

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+---
+name: grill-with-docs
+description: A relentless interview to sharpen a plan or design, which also creates docs (ADR's and glossary) as we go.
+disable-model-invocation: true
+---
+
+Run a `/grilling` session, using the `/domain-modeling` skill.

common/engineering/improve-codebase-architecture/HTML-REPORT.md

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+# HTML Report Format
+
+The architectural review is rendered as a single self-contained HTML file in the OS temp directory. Tailwind and Mermaid both come from CDNs. Mermaid handles graph-shaped diagrams reliably; hand-built divs and inline SVG handle the more editorial visuals (mass diagrams, cross-sections). Mix the two — don't lean on Mermaid for everything, it'll start to look generic.
+
+## Scaffold
+
+```html
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <title>Architecture review — {{repo name}}</title>
+    <script src="https://cdn.tailwindcss.com"></script>
+    <script type="module">
+      import mermaid from "https://cdn.jsdelivr.net/npm/mermaid@11/dist/mermaid.esm.min.mjs";
+      mermaid.initialize({ startOnLoad: true, theme: "neutral", securityLevel: "loose" });
+    </script>
+    <style>
+      /* small custom layer for things Tailwind doesn't cover cleanly:
+         dashed seam lines, hand-drawn-feeling arrow heads, etc. */
+      .seam { stroke-dasharray: 4 4; }
+      .leak { stroke: #dc2626; }
+      .deep { background: linear-gradient(135deg, #0f172a, #1e293b); }
+    </style>
+  </head>
+  <body class="bg-stone-50 text-slate-900 font-sans">
+    <main class="max-w-5xl mx-auto px-6 py-12 space-y-12">
+      <header>...</header>
+      <section id="candidates" class="space-y-10">...</section>
+      <section id="top-recommendation">...</section>
+    </main>
+  </body>
+</html>
+```
+
+## Header
+
+Repo name, date, and a compact legend: solid box = module, dashed line = seam, red arrow = leakage, thick dark box = deep module. No introduction paragraph — straight into the candidates.
+
+## Candidate card
+
+The diagrams carry the weight. Prose is sparse, plain, and uses the glossary terms (from the `/codebase-design` skill) without ceremony.
+
+Each candidate is one `<article>`:
+
+- **Title** — short, names the deepening (e.g. "Collapse the Order intake pipeline").
+- **Badge row** — recommendation strength (`Strong` = emerald, `Worth exploring` = amber, `Speculative` = slate), plus a tag for the dependency category (`in-process`, `local-substitutable`, `ports & adapters`, `mock`).
+- **Files** — monospaced list, `font-mono text-sm`.
+- **Before / After diagram** — the centrepiece. Two columns, side by side. See patterns below.
+- **Problem** — one sentence. What hurts.
+- **Solution** — one sentence. What changes.
+- **Wins** — bullets, ≤6 words each. e.g. "Tests hit one interface", "Pricing logic stops leaking", "Delete 4 shallow wrappers".
+- **ADR callout** (if applicable) — one line in an amber-tinted box.
+
+No paragraphs of explanation. If the diagram needs a paragraph to be understood, redraw the diagram.
+
+## Diagram patterns
+
+Pick the pattern that fits the candidate. Mix them. Don't make every diagram look the same — variety is part of the point.
+
+### Mermaid graph (the workhorse for dependencies / call flow)
+
+Use a Mermaid `flowchart` or `graph` when the point is "X calls Y calls Z, and look at the mess." Wrap it in a Tailwind-styled card so it doesn't feel parachuted in. Style with classDef to colour leakage edges red and the deep module dark. Sequence diagrams work well for "before: 6 round-trips; after: 1."
+
+```html
+<div class="rounded-lg border border-slate-200 bg-white p-4">
+  <pre class="mermaid">
+    flowchart LR
+      A[OrderHandler] --> B[OrderValidator]
+      B --> C[OrderRepo]
+      C -.leak.-> D[PricingClient]
+      classDef leak stroke:#dc2626,stroke-width:2px;
+      class C,D leak
+  </pre>
+</div>
+```
+
+### Hand-built boxes-and-arrows (when Mermaid's layout fights you)
+
+Modules as `<div>`s with borders and labels. Arrows as inline SVG `<line>` or `<path>` elements positioned absolutely over a relative container. Reach for this when you want the "after" diagram to feel like one thick-bordered deep module with greyed-out internals — Mermaid won't render that with the right weight.
+
+### Cross-section (good for layered shallowness)
+
+Stack horizontal bands (`h-12 border-l-4`) to show layers a call passes through. Before: 6 thin layers each doing nothing. After: 1 thick band labelled with the consolidated responsibility.
+
+### Mass diagram (good for "interface as wide as implementation")
+
+Two rectangles per module — one for interface surface area, one for implementation. Before: interface rectangle is nearly as tall as the implementation rectangle (shallow). After: interface rectangle is short, implementation rectangle is tall (deep).
+
+### Call-graph collapse
+
+Before: a tree of function calls rendered as nested boxes. After: the same tree collapsed into one box, with the now-internal calls shown faded inside it.
+
+## Style guidance
+
+- Lean editorial, not corporate-dashboard. Generous whitespace. Serif optional for headings (`font-serif` works well with stone/slate).
+- Colour sparingly: one accent (emerald or indigo) plus red for leakage and amber for warnings.
+- Keep diagrams ~320px tall so before/after sits comfortably side by side without scrolling.
+- Use `text-xs uppercase tracking-wider` for module labels inside diagrams — they should read as schematic, not as UI.
+- The only scripts are the Tailwind CDN and the Mermaid ESM import. The report is otherwise static — no app code, no interactivity beyond Mermaid's own rendering.
+
+## Top recommendation section
+
+One larger card. Candidate name, one sentence on why, anchor link to its card. That's it.
+
+## Tone
+
+Plain English, concise — but the architectural nouns and verbs come straight from the `/codebase-design` skill. Concision is not an excuse to drift.
+
+**Use exactly:** module, interface, implementation, depth, deep, shallow, seam, adapter, leverage, locality.
+
+**Never substitute:** component, service, unit (for module) · API, signature (for interface) · boundary (for seam) · layer, wrapper (for module, when you mean module).
+
+**Phrasings that fit the style:**
+
+- "Order intake module is shallow — interface nearly matches the implementation."
+- "Pricing leaks across the seam."
+- "Deepen: one interface, one place to test."
+- "Two adapters justify the seam: HTTP in prod, in-memory in tests."
+
+**Wins bullets** name the gain in glossary terms: *"locality: bugs concentrate in one module"*, *"leverage: one interface, N call sites"*, *"interface shrinks; implementation absorbs the wrappers"*. Don't write *"easier to maintain"* or *"cleaner code"* — those terms aren't in the glossary and don't earn their place.
+
+No hedging, no throat-clearing, no "it's worth noting that…". If a sentence could be a bullet, make it a bullet. If a bullet could be cut, cut it. If a term isn't in the `/codebase-design` glossary, reach for one that is before inventing a new one.

common/engineering/improve-codebase-architecture/SKILL.md

@@ -0,0 +1,66 @@
+---
+name: improve-codebase-architecture
+description: Scan a codebase for deepening opportunities, present them as a visual HTML report, then grill through whichever one you pick.
+disable-model-invocation: true
+---
+
+# Improve Codebase Architecture
+
+Surface architectural friction and propose **deepening opportunities** — refactors that turn shallow modules into deep ones. The aim is testability and AI-navigability.
+
+This command is _informed_ by the project's domain model and built on a shared design vocabulary:
+
+- Run the `/codebase-design` skill for the architecture vocabulary (**module**, **interface**, **depth**, **seam**, **adapter**, **leverage**, **locality**) and its principles (the deletion test, "the interface is the test surface", "one adapter = hypothetical seam, two = real"). Use these terms exactly in every suggestion — don't drift into "component," "service," "API," or "boundary."
+- The domain language in `CONTEXT.md` gives names to good seams; ADRs in `docs/adr/` record decisions this command should not re-litigate.
+
+## Process
+
+### 1. Explore
+
+Read the project's domain glossary (`CONTEXT.md`) and any ADRs in the area you're touching first.
+
+Then use the Agent tool with `subagent_type=Explore` to walk the codebase. Don't follow rigid heuristics — explore organically and note where you experience friction:
+
+- Where does understanding one concept require bouncing between many small modules?
+- Where are modules **shallow** — interface nearly as complex as the implementation?
+- Where have pure functions been extracted just for testability, but the real bugs hide in how they're called (no **locality**)?
+- Where do tightly-coupled modules leak across their seams?
+- Which parts of the codebase are untested, or hard to test through their current interface?
+
+Apply the **deletion test** to anything you suspect is shallow: would deleting it concentrate complexity, or just move it? A "yes, concentrates" is the signal you want.
+
+### 2. Present candidates as an HTML report
+
+Write a self-contained HTML file to the OS temp directory so nothing lands in the repo. Resolve the temp dir from `$TMPDIR`, falling back to `/tmp` (or `%TEMP%` on Windows), and write to `<tmpdir>/architecture-review-<timestamp>.html` so each run gets a fresh file. Open it for the user — `xdg-open <path>` on Linux, `open <path>` on macOS, `start <path>` on Windows — and tell them the absolute path.
+
+The report uses **Tailwind via CDN** for layout and styling, and **Mermaid via CDN** for diagrams where a graph/flow/sequence reliably communicates the structure. Mix Mermaid with hand-crafted CSS/SVG visuals — use Mermaid when relationships are graph-shaped (call graphs, dependencies, sequences), and hand-built divs/SVG when you want something more editorial (mass diagrams, cross-sections, collapse animations). Each candidate gets a **before/after visualisation**. Be visual.
+
+For each candidate, render a card with:
+
+- **Files** — which files/modules are involved
+- **Problem** — why the current architecture is causing friction
+- **Solution** — plain English description of what would change
+- **Benefits** — explained in terms of locality and leverage, and how tests would improve
+- **Before / After diagram** — side-by-side, custom-drawn, illustrating the shallowness and the deepening
+- **Recommendation strength** — one of `Strong`, `Worth exploring`, `Speculative`, rendered as a badge
+
+End the report with a **Top recommendation** section: which candidate you'd tackle first and why.
+
+**Use CONTEXT.md vocabulary for the domain, and the `/codebase-design` vocabulary for the architecture.** If `CONTEXT.md` defines "Order," talk about "the Order intake module" — not "the FooBarHandler," and not "the Order service."
+
+**ADR conflicts**: if a candidate contradicts an existing ADR, only surface it when the friction is real enough to warrant revisiting the ADR. Mark it clearly in the card (e.g. a warning callout: _"contradicts ADR-0007 — but worth reopening because…"_). Don't list every theoretical refactor an ADR forbids.
+
+See [HTML-REPORT.md](HTML-REPORT.md) for the full HTML scaffold, diagram patterns, and styling guidance.
+
+Do NOT propose interfaces yet. After the file is written, ask the user: "Which of these would you like to explore?"
+
+### 3. Grilling loop
+
+Once the user picks a candidate, run the `/grilling` skill to walk the design tree with them — constraints, dependencies, the shape of the deepened module, what sits behind the seam, what tests survive.
+
+Side effects happen inline as decisions crystallize — run the `/domain-modeling` skill to keep the domain model current as you go:
+
+- **Naming a deepened module after a concept not in `CONTEXT.md`?** Add the term to `CONTEXT.md`. Create the file lazily if it doesn't exist.
+- **Sharpening a fuzzy term during the conversation?** Update `CONTEXT.md` right there.
+- **User rejects the candidate with a load-bearing reason?** Offer an ADR, framed as: _"Want me to record this as an ADR so future architecture reviews don't re-suggest it?"_ Only offer when the reason would actually be needed by a future explorer to avoid re-suggesting the same thing — skip ephemeral reasons ("not worth it right now") and self-evident ones.
+- **Want to explore alternative interfaces for the deepened module?** Run the `/codebase-design` skill and use its design-it-twice parallel sub-agent pattern.

common/engineering/resolving-merge-conflicts/SKILL.md

@@ -0,0 +1,14 @@
+---
+name: resolving-merge-conflicts
+description: "Use when you need to resolve an in-progress git merge/rebase conflict."
+---
+
+1. **See the current state** of the merge/rebase. Check git history, and the conflicting files.
+
+2. **Find the primary sources** for each conflict. Understand deeply why each change was made, and what the original intent was. Read the commit messages, check the PRs, check original issues/tickets.
+
+3. **Resolve each hunk.** Preserve both intents where possible. Where incompatible, pick the one matching the merge's stated goal and note the trade-off. Do **not** invent new behaviour. Always resolve; never `--abort`.
+
+4. Discover the project's **automated checks** and run them — typically typecheck, then tests, then format. Fix anything the merge broke.
+
+5. **Finish the merge/rebase.** Stage everything and commit. If rebasing, continue the rebase process until all commits are rebased.

common/engineering/setup-skills/SKILL.md

@@ -0,0 +1,153 @@
+---
+name: setup-skills
+description: Configure this repo for the engineering skills, set up its issue tracker, triage label vocabulary, and domain doc layout. Run once before first use of the other engineering skills.
+disable-model-invocation: true
+---
+
+# Setup Engineering Skills
+
+Scaffold the per-repo configuration that the engineering skills assume:
+
+- Issue tracker: where issues live (never assume a default forge)
+- Triage labels: the strings used for the canonical triage roles, labels are defined in `triage-labels.md`
+- Domain docs: where `CONTEXT.md` and ADRs live, and the consumer rules for reading them
+- **ADR wiki** — where ADRs are stored (forge wiki, cloned into `docs/adr/`), and the clone/push workflow
+
+This is a prompt-driven skill, not a deterministic script. Explore, present what you found, confirm with the user, then write.
+
+## Process
+
+### 1. Explore
+
+Look at the current repo to understand its starting state. Read whatever exists; don't assume:
+
+- find out what force is being used for the issue tracker (GitHub, GitLab, or Gitea)
+- `AGENTS.md` and `CLAUDE.md`  at the repo root — does either exist? Is there already an ## Agent skills section in either?
+* `CONTEXT.md` and `CONTEXT-MAP.md` at the repo root.
+- `docs/adr/` (check whether it's a wiki clone via `docs/adr/.git/config`) and any `src/*/docs/adr/` directories
+- `docs/agents/` — does this skill's prior output already exist?
+
+### 2. Present findings and ask
+
+Summarise what's present and what's missing. Then walk the user through the four decisions **one at a time** - present a section, get the user's answer, then move to the next. Don't dump all three at once.
+
+Assume the user does not know what these terms mean. Each section starts with a short explainer (what it is, why these skills need it, what changes if they pick differently). Then show the choices and the default.
+
+Section A - Issue tracker:
+
+> Explainer: The "issue tracker" is where issues live for this repo. Skills like `to-issues`, `triage`, `to-prd`, and `qa` read from and write to it — they need to know whether to call `gh issue create`, write a markdown file under `.scratch/`, or follow some other workflow you describe. Pick the place you actually track work for this repo.
+
+Default posture: these skills were designed for GitHub. If a `git remote` points at GitHub, propose that. If a `git remote` points at GitLab (`gitlab.com` or a self-hosted host), propose GitLab. If a `git remote` point at a Gitea (a self-hosted host with a `gitea` in the url). Otherwise ask the user, offer:
+
+- **GitHub** — issues live in the repo's GitHub Issues (uses the `gh` CLI)
+- **GitLab** — issues live in the repo's GitLab Issues (uses the [`glab`](https://gitlab.com/gitlab-org/cli) CLI)
+* Gitea — issues live in the repo's Gitea Issues (uses the `tea` CLI)
+- **Other** (Jira, Linear, etc.) — ask the user to describe the workflow in one paragraph; the skill will record it as freeform prose
+
+If — and only if — the user picked **GitHub**, **GitLab** or **Gitea**, ask one follow-up:
+
+> Explainer: Open-source repos often receive feature requests as pull requests, not just issues — a PR is an issue with attached code. If you turn this on, `/triage` pulls *external* PRs into the same queue and runs them through the same labels and states as issues (collaborators' in-flight PRs are left alone). Leave it off if PRs aren't a request surface for you.
+
+- **PRs as a request surface** — yes / no (default: no). Record the answer in `docs/agents/issue-tracker.md`. For local-markdown and other trackers, skip this question — there are no PRs.
+
+**Section B — Triage label vocabulary.**
+
+> Explainer: When the `triage` skill processes an incoming issue, it moves it through a state machine — needs evaluation, waiting on reporter, ready for an AFK agent to pick up, ready for a human, or won't fix. To do that, it needs to apply labels (or the equivalent in your issue tracker) that match strings *you've actually configured*. If your repo already uses different label names (e.g. `bug:triage` instead of `needs-triage`), map them here so the skill applies the right ones instead of creating duplicates.
+
+Look at the `triage-labels.md` file for the labels and each roles they define.
+
+Default: each role's string equals its name. Ask the user if they want to override any. If their issue tracker has no existing labels, the defaults are fine.
+
+**Section C — Domain docs.**
+
+> Explainer: Some skills (`improve-codebase-architecture`, `diagnosing-bugs`, `tdd`) read a `CONTEXT.md` file to learn the project's domain languagee, and `adr` for past architectural decisions. They need to know whether the repo has one global context or multiple (e.g. a monorepo with separate frontend/backend contexts) so they look in the right place.
+
+Confirm the layout:
+
+- **Single-context** — one `CONTEXT.md` + `adr` at the repo root. Most repos are this.
+- **Multi-context** — `CONTEXT-MAP.md` at the root pointing to per-context `CONTEXT.md` files (typically a monorepo).
+
+**Section D — ADR wiki.**
+
+> Explainer: ADRs document significant architectural decisions. Rather than storing them in the source repo (where they clutter PRs, pollute git history, and live under a different lifecycle than code), they live on the forge's wiki. The wiki is cloned into `docs/adr/` during setup — skills read and write ADRs by relative path, never knowing the difference. At end of session, the agent pushes any new or modified ADRs to the wiki remote.
+
+Derive the wiki URL from the forge detected in Section A:
+
+| Forge | Wiki URL pattern |
+|---|---|
+| **GitHub** | `https://github.com/<owner>/<repo>.wiki.git` |
+| **Gitea** | `https://<host>/<owner>/<repo>.wiki.git` |
+| **GitLab** | `https://gitlab.com/<owner>/<repo>.wiki.git` |
+
+After the forge is confirmed, present the workflow and confirm:
+
+> Explainer: The agent will need to authenticate to push ADR changes to the wiki. This can use the same credentials the forge CLI (`gh` / `tea`) already stores, or a dedicated token. On every session start, `docs/adr/` is pulled to catch any web UI edits. At end of session, new/modified ADRs are committed and pushed with `git pull --rebase` to handle concurrent edits.
+
+- **Wiki clone bootstrap** — yes, clone into `docs/adr/` and add `docs/adr/` to `.gitignore`. (Always yes for wiki-based ADRs.)
+- **Auth method** — from forge CLI (`gh` / `tea`) / SSH key / dedicated token (default: forge CLI)
+- **Commit message convention** — `docs(adr): <action> ADR-NNNN — <short description>` (user can customise)
+
+Record the answers in `docs/agents/adr-wiki.md`.
+
+### 3. Confirm and edit
+
+Show the user a draft of:
+
+- The `## Agent skills` block to add to whichever of `CLAUDE.md` / `AGENTS.md` is being edited (see step 4 for selection rules)
+- The contents of `docs/agents/issue-tracker.md`, `docs/agents/triage-labels.md`, `docs/agents/domain.md`, and `docs/agents/adr-wiki.md`
+
+Let them edit before writing.
+
+### 4. Write
+
+**Pick the file to edit:**
+
+- If `CLAUDE.md` exists, edit it.
+- Else if `AGENTS.md` exists, edit it.
+- If neither exists, ask the user which one to create — don't pick for them.
+
+Never create `AGENTS.md` when `CLAUDE.md` already exists (or vice versa) — always edit the one that's already there.
+
+If an `## Agent skills` block already exists in the chosen file, update its contents in-place rather than appending a duplicate. Don't overwrite user edits to the surrounding sections.
+
+The block:
+
+```markdown
+## Agent skills
+
+### Issue tracker
+
+[one-line summary of where issues are tracked, plus whether external PRs are a triage surface]. See `docs/agents/issue-tracker.md`.
+
+### Triage labels
+
+[one-line summary of the label vocabulary]. See `docs/agents/triage-labels.md`.
+
+### Domain docs
+
+[one-line summary of layout — "single-context" or "multi-context"]. See `docs/agents/domain.md`.
+
+### ADR wiki
+
+[one-line summary — forge, wiki URL, auth method]. See `docs/agents/adr-wiki.md`.
+
+ ## Project Context Pack
+
+[Agent memory file that describes the repo's context, codebase, and navigation rules]. See `.agents/project-context.md`.
+
+```
+
+Then write the four docs files using the seed templates in this skill folder as a starting point:
+
+- [issue-tracker-github.jd](./issue-tracker-github.md) — GitHub issue tracker
+- [issue-tracker-gitlab.md](./issue-tracker-gitlab.md) — GitLab issue tracker
+- [issue-tracker-gitea.md](./issue-tracker-gitea.md) — Gitea issue tracker
+- [triage-labels.md](./triage-labels.md) — label mapping
+- [domain.md](./domain.md) — domain doc consumer rules + layout
+- [adr-wiki.md](./adr-wiki.md) — ADR wiki clone and push workflow
+
+For "other" issue trackers, write `docs/agents/issue-tracker.md` from scratch using the user's description.
+
+### 5. Done
+
+Tell the user the setup is complete, which engineering skills will now read from these files, and that ADR changes are pushed to the forge wiki at end of session. Mention they can edit `docs/agents/*.md` directly later — re-running this skill is only necessary if they want to switch issue trackers, restart from scratch, or reconfigure the ADR wiki.

common/engineering/setup-skills/adr-wiki.md

@@ -0,0 +1,68 @@
+# ADR Wiki
+
+Architecture Decision Records live on the forge wiki and are cloned into `docs/adr/` during setup.
+
+## Wiki URL
+
+```
+<wiki-url>
+```
+
+Derived from the forge remote during `/setup-matt-pocock-skills`.
+
+## Bootstrap
+
+On first setup, `/setup-matt-pocock-skills` clones the wiki:
+
+```bash
+git clone <wiki-url> docs/adr/
+```
+
+And adds `docs/adr/` to `.gitignore`.
+
+On subsequent sessions, pull the latest:
+
+```bash
+cd docs/adr/ && git pull --rebase
+```
+
+## Auth
+
+Authentication for pushing ADR changes uses: `<auth-method>`
+
+- **Forge CLI token** — `gh` or `tea` already stores credentials; use them for git push via HTTPS with token auth.
+- **SSH key** — wiki remote uses `git@<host>:<owner>/<repo>.wiki.git`.
+- **Dedicated token** — stored in env var `GIT_WIKI_TOKEN`; used as password in HTTPS URL.
+
+## Session-end push
+
+At end of every session, the agent:
+
+1. `cd docs/adr/ && git add -A && git commit -m "docs(adr): <action> ADR-NNNN — <description>"`
+2. `git pull --rebase` (handle any web UI edits)
+3. `git push`
+
+If a conflict arises during rebase, surface it to the user for resolution.
+
+## Commit message convention
+
+```
+docs(adr): add ADR-NNNN — title
+docs(adr): update ADR-NNNN — reason
+docs(adr): remove ADR-NNNN — superseded by ADR-NNNN
+```
+
+## Consumer skills
+
+These skills read from `docs/adr/` by relative path — the wiki clone is transparent:
+
+- `diagnosing-bugs`
+- `tdd`
+- `improve-codebase-architecture`
+- `domain-modeling`
+- `grill-with-docs`
+
+These skills may create ADRs in `docs/adr/`; the wiki push is handled at session end:
+
+- `domain-modeling`
+- `improve-codebase-architecture`

common/engineering/setup-skills/domain.md

@@ -0,0 +1,67 @@
+# Domain Docs
+
+How the engineering skills should consume this repo's domain documentation when exploring the codebase.
+
+## Before exploring, read these
+
+- **`CONTEXT.md`** at the repo root, or
+- **`CONTEXT-MAP.md`** at the repo root if it exists — it points at one `CONTEXT.md` per context. Read each one relevant to the topic.
+- **`docs/adr/`** — read ADRs that touch the area you're about to work in. In multi-context repos, also check `/doc/adr/<context>/` for context-scoped decisions.
+
+If any of these files don't exist, **proceed silently**. Don't flag their absence; don't suggest creating them upfront. The `/domain-modeling` skill (reached via `/grill-with-docs` and `/improve-codebase-architecture`) creates them lazily when terms or decisions actually get resolved.
+
+## File structure
+
+Single-context repo (most repos):
+
+```
+/
+├── CONTEXT.md
+├── docs/adr/
+│   ├── 0001-event-sourced-orders.md
+│   └── 0002-postgres-for-write-model.md
+├── src/
+└── .gitignore                     ← docs/adr/ ignored
+```
+
+Multi-context repo (presence of `CONTEXT-MAP.md` at the root):
+
+```
+/
+├── CONTEXT-MAP.md
+├── src/
+├── .gitignore                         ← docs/adr/ ignored
+└── docs/adr/                          ← system-wide decisions
+    ├── ordering/                      ← context scope decisions
+    │   ├── CONTEXT.md
+    │   └── 0001-event-source-orders.md
+    └── billing/                       ← context scope decisions
+        ├── CONTEXT.md
+        └── 0002-postgres-for-write-model.md
+```
+
+
+## ADR lifecycle
+
+ADRs live on the forge wiki and are cloned into `docs/adr/` during setup (`/setup-matt-pocock-skills`). The source repo ignores `docs/adr/` via `.gitignore`.
+
+- **Reading** — skills read ADRs by relative path (`docs/adr/...`) as before. The wiki clone is transparent.
+- **Creating / updating** — skills write ADRs to `docs/adr/` as files. Changes accumulate in the wiki clone's local git state.
+- **Pushing** — at end of session, the agent commits new/modified ADRs to the wiki clone and pushes to the forge wiki remote, using `git pull --rebase` before push to handle any concurrent web edits.
+- **Commit message convention**: `docs(adr): <action> ADR-NNNN — <short description>`
+
+## Use the glossary's vocabulary
+
+When your output names a domain concept (in an issue title, a refactor proposal, a hypothesis, a test name), use the term as defined in `CONTEXT.md`. Don't drift to synonyms the glossary explicitly avoids.
+
+If the concept you need isn't in the glossary yet, that's a signal — either you're inventing language the project doesn't use (reconsider) or there's a real gap (note it for `/domain-modeling`).
+
+## Flag ADR conflicts
+
+If your output contradicts an existing ADR, surface it explicitly rather than silently overriding:
+
+> _Contradicts ADR-0007 (event-sourced orders) — but worth reopening because…_
+
+## ADR storage
+
+ADR documents are stored in a clone repo of the forge wiki, if the `docs/adr` folder does not exist ask the user for the repo url and clone it. Commit each changes without asking the user for a commit message and push to the remote. 

common/engineering/setup-skills/issue-tracker-gitea.md

@@ -0,0 +1,35 @@
+# Issue tracker: Gitea
+
+Issues and PRDs for this repo live as Gitea issues. Use the `gitea` CLI for all operations.
+
+## Conventions
+
+- **Create an issue**: `tea issue create --title "..." --description "..."`. Use a heredoc for multi-line descriptions. 
+- **Read an issue**: `tea issue <number> --comments`. Use `-o json` for machine-readable output.
+- **List issues**: `tea issue list --state open -o json` with appropriate `--labels` and `--state` filters. 
+- **Comment on an issue**: `tea comment <number> "..."`.
+- **Apply / remove labels**: `tea issue edit <number> --add-label "..."` / `--remove-label "..."`. Multiple labels can be comma-separated or by repeating the flag.les
+- **Close**: `tea issue close <number>`. `tea issue close` does not accept a closing comment, so post the explanation first with `tea comment <number> "..."`, then close.
+
+Infer the repo from git remote -v — `tea` does this automatically when run inside a clone.
+
+## Pull requests as a triage surface
+
+**PRs as a request surface: no.** _(Set to `yes` if this repo treats external PRs as feature requests; `/triage` reads this flag.)_
+
+When set to `yes`, PRs run through the same labels and states as issues, using the `gh pr` equivalents:
+
+- **Read a PR**: `tea pr <number> --comments` and `tea api /repos/{owner}/{repo}/pulls/<number>.diff`  for the diff.
+
+- **List external PRs for triage**: `tea pr list --state open -o json ` then keep only PRs whose author is not a project member/owner (a contributor's MR, not a maintainer's in-flight work).
+- **Comment / label / close**: `tea comment <number> "..."`, `tea pr edit --add-label`/`--remove-label`, `tea pr close`.
+
+Gitea shares one number space across issues and PRs, so a bare `#42` may be either — resolve with `tea pr 42` and fall back to `tea issue 42`.
+
+## When a skill says "publish to the issue tracker"
+
+Create a Gitea issue.
+
+## When a skill says "fetch the relevant ticket"
+
+Run `tea issue <number> --comments`.

common/engineering/setup-skills/issue-tracker-github.md

@@ -0,0 +1,34 @@
+# Issue tracker: GitHub
+
+Issues and PRDs for this repo live as GitHub issues. Use the `gh` CLI for all operations.
+
+## Conventions
+
+- **Create an issue**: `gh issue create --title "..." --body "..."`. Use a heredoc for multi-line bodies.
+- **Read an issue**: `gh issue view <number> --comments`, filtering comments by `jq` and also fetching labels.
+- **List issues**: `gh issue list --state open --json number,title,body,labels,comments --jq '[.[] | {number, title, body, labels: [.labels[].name], comments: [.comments[].body]}]'` with appropriate `--label` and `--state` filters.
+- **Comment on an issue**: `gh issue comment <number> --body "..."`
+- **Apply / remove labels**: `gh issue edit <number> --add-label "..."` / `--remove-label "..."`
+- **Close**: `gh issue close <number> --comment "..."`
+
+Infer the repo from `git remote -v` — `gh` does this automatically when run inside a clone.
+
+## Pull requests as a triage surface
+
+**PRs as a request surface: no.** _(Set to `yes` if this repo treats external PRs as feature requests; `/triage` reads this flag.)_
+
+When set to `yes`, PRs run through the same labels and states as issues, using the `gh pr` equivalents:
+
+- **Read a PR**: `gh pr view <number> --comments` and `gh pr diff <number>` for the diff.
+- **List external PRs for triage**: `gh pr list --state open --json number,title,body,labels,author,authorAssociation,comments` then keep only `authorAssociation` of `CONTRIBUTOR`, `FIRST_TIME_CONTRIBUTOR`, or `NONE` (drop `OWNER`/`MEMBER`/`COLLABORATOR`).
+- **Comment / label / close**: `gh pr comment`, `gh pr edit --add-label`/`--remove-label`, `gh pr close`.
+
+GitHub shares one number space across issues and PRs, so a bare `#42` may be either — resolve with `gh pr view 42` and fall back to `gh issue view 42`.
+
+## When a skill says "publish to the issue tracker"
+
+Create a GitHub issue.
+
+## When a skill says "fetch the relevant ticket"
+
+Run `gh issue view <number> --comments`.

common/engineering/setup-skills/issue-tracker-gitlab.md

@@ -0,0 +1,35 @@
+# Issue tracker: GitLab
+
+Issues and PRDs for this repo live as GitLab issues. Use the [`glab`](https://gitlab.com/gitlab-org/cli) CLI for all operations.
+
+## Conventions
+
+- **Create an issue**: `glab issue create --title "..." --description "..."`. Use a heredoc for multi-line descriptions. Pass `--description -` to open an editor.
+- **Read an issue**: `glab issue view <number> --comments`. Use `-F json` for machine-readable output.
+- **List issues**: `glab issue list -F json` with appropriate `--label` filters.
+- **Comment on an issue**: `glab issue note <number> --message "..."`. GitLab calls comments "notes".
+- **Apply / remove labels**: `glab issue update <number> --label "..."` / `--unlabel "..."`. Multiple labels can be comma-separated or by repeating the flag.
+- **Close**: `glab issue close <number>`. `glab issue close` does not accept a closing comment, so post the explanation first with `glab issue note <number> --message "..."`, then close.
+- **Merge requests**: GitLab calls PRs "merge requests". Use `glab mr create`, `glab mr view`, `glab mr note`, etc. — the same shape as `gh pr ...` with `mr` in place of `pr` and `note`/`--message` in place of `comment`/`--body`.
+
+Infer the repo from `git remote -v` — `glab` does this automatically when run inside a clone.
+
+## Merge requests as a triage surface
+
+**MRs as a request surface: no.** _(Set to `yes` if this repo treats external merge requests as feature requests; `/triage` reads this flag.)_
+
+When set to `yes`, MRs run through the same labels and states as issues, using the `glab mr` equivalents:
+
+- **Read an MR**: `glab mr view <number> --comments` and `glab mr diff <number>` for the diff.
+- **List external MRs for triage**: `glab mr list -F json`, then keep only MRs whose author is not a project member/owner (a contributor's MR, not a maintainer's in-flight work).
+- **Comment / label / close**: `glab mr note`, `glab mr update --label`/`--unlabel`, `glab mr close`.
+
+Unlike GitHub, GitLab numbers issues and MRs separately, so `#42` is unambiguous once you know which surface the maintainer means.
+
+## When a skill says "publish to the issue tracker"
+
+Create a GitLab issue.
+
+## When a skill says "fetch the relevant ticket"
+
+Run `glab issue view <number> --comments`.

common/engineering/setup-skills/triage-labels.md

@@ -0,0 +1,15 @@
+# Triage Labels
+
+The skills speak in terms of five canonical triage roles. This file maps those roles to the actual label strings used in this repo's issue tracker.
+
+| Label in skills | Label in our tracker | Meaning                                  |
+| -------------------------- | -------------------- | ---------------------------------------- |
+| `needs-triage`             | `needs-triage`       | Maintainer needs to evaluate this issue  |
+| `needs-info`               | `needs-info`         | Waiting on reporter for more information |
+| `ready-for-agent`          | `ready-for-agent`    | Fully specified, ready for an AFK agent  |
+| `ready-for-human`          | `ready-for-human`    | Requires human implementation            |
+| `wontfix`                  | `wontfix`            | Will not be actioned                     |
+
+When a skill mentions a role (e.g. "apply the AFK-ready triage label"), use the corresponding label string from this table.
+
+Edit the right-hand column to match whatever vocabulary you actually use.

common/engineering/tdd/SKILL.md

@@ -0,0 +1,108 @@
+---
+name: tdd
+description: Test-driven development. Use when the user wants to build features or fix bugs test-first, mentions "red-green-refactor", or wants integration tests.
+---
+
+# Test-Driven Development
+
+## Philosophy
+
+**Core principle**: Tests should verify behavior through public interfaces, not implementation details. Code can change entirely; tests shouldn't.
+
+**Good tests** are integration-style: they exercise real code paths through public APIs. They describe _what_ the system does, not _how_ it does it. A good test reads like a specification - "user can checkout with valid cart" tells you exactly what capability exists. These tests survive refactors because they don't care about internal structure.
+
+**Bad tests** are coupled to implementation. They mock internal collaborators, test private methods, or verify through external means (like querying a database directly instead of using the interface). The warning sign: your test breaks when you refactor, but behavior hasn't changed. If you rename an internal function and tests fail, those tests were testing implementation, not behavior.
+
+See [tests.md](tests.md) for examples and [mocking.md](mocking.md) for mocking guidelines.
+
+## Anti-Pattern: Horizontal Slices
+
+**DO NOT write all tests first, then all implementation.** This is "horizontal slicing" - treating RED as "write all tests" and GREEN as "write all code."
+
+This produces **crap tests**:
+
+- Tests written in bulk test _imagined_ behavior, not _actual_ behavior
+- You end up testing the _shape_ of things (data structures, function signatures) rather than user-facing behavior
+- Tests become insensitive to real changes - they pass when behavior breaks, fail when behavior is fine
+- You outrun your headlights, committing to test structure before understanding the implementation
+
+**Correct approach**: Vertical slices via tracer bullets. One test → one implementation → repeat. Each test responds to what you learned from the previous cycle. Because you just wrote the code, you know exactly what behavior matters and how to verify it.
+
+```
+WRONG (horizontal):
+  RED:   test1, test2, test3, test4, test5
+  GREEN: impl1, impl2, impl3, impl4, impl5
+
+RIGHT (vertical):
+  RED→GREEN: test1→impl1
+  RED→GREEN: test2→impl2
+  RED→GREEN: test3→impl3
+  ...
+```
+
+## Workflow
+
+### 1. Planning
+
+When exploring the codebase, read `CONTEXT.md` (if it exists) so that test names and interface vocabulary match the project's domain language, and respect ADRs in the area you're touching.
+
+Before writing any code:
+
+- [ ] Confirm with user what interface changes are needed
+- [ ] Confirm with user which behaviors to test (prioritize)
+- [ ] Identify opportunities for deep modules (small interface, deep implementation) — run the `/codebase-design` skill for the vocabulary and the testability checks
+- [ ] List the behaviors to test (not implementation steps)
+- [ ] Get user approval on the plan
+
+Ask: "What should the public interface look like? Which behaviors are most important to test?"
+
+**You can't test everything.** Confirm with the user exactly which behaviors matter most. Focus testing effort on critical paths and complex logic, not every possible edge case.
+
+### 2. Tracer Bullet
+
+Write ONE test that confirms ONE thing about the system:
+
+```
+RED:   Write test for first behavior → test fails
+GREEN: Write minimal code to pass → test passes
+```
+
+This is your tracer bullet - proves the path works end-to-end.
+
+### 3. Incremental Loop
+
+For each remaining behavior:
+
+```
+RED:   Write next test → fails
+GREEN: Minimal code to pass → passes
+```
+
+Rules:
+
+- One test at a time
+- Only enough code to pass current test
+- Don't anticipate future tests
+- Keep tests focused on observable behavior
+
+### 4. Refactor
+
+After all tests pass, look for [refactor candidates](refactoring.md):
+
+- [ ] Extract duplication
+- [ ] Deepen modules (move complexity behind simple interfaces)
+- [ ] Apply SOLID principles where natural
+- [ ] Consider what new code reveals about existing code
+- [ ] Run tests after each refactor step
+
+**Never refactor while RED.** Get to GREEN first.
+
+## Checklist Per Cycle
+
+```
+[ ] Test describes behavior, not implementation
+[ ] Test uses public interface only
+[ ] Test would survive internal refactor
+[ ] Code is minimal for this test
+[ ] No speculative features added
+```

common/engineering/tdd/mocking.md

@@ -0,0 +1,59 @@
+# When to Mock
+
+Mock at **system boundaries** only:
+
+- External APIs (payment, email, etc.)
+- Databases (sometimes - prefer test DB)
+- Time/randomness
+- File system (sometimes)
+
+Don't mock:
+
+- Your own classes/modules
+- Internal collaborators
+- Anything you control
+
+## Designing for Mockability
+
+At system boundaries, design interfaces that are easy to mock:
+
+**1. Use dependency injection**
+
+Pass external dependencies in rather than creating them internally:
+
+```typescript
+// Easy to mock
+function processPayment(order, paymentClient) {
+  return paymentClient.charge(order.total);
+}
+
+// Hard to mock
+function processPayment(order) {
+  const client = new StripeClient(process.env.STRIPE_KEY);
+  return client.charge(order.total);
+}
+```
+
+**2. Prefer SDK-style interfaces over generic fetchers**
+
+Create specific functions for each external operation instead of one generic function with conditional logic:
+
+```typescript
+// GOOD: Each function is independently mockable
+const api = {
+  getUser: (id) => fetch(`/users/${id}`),
+  getOrders: (userId) => fetch(`/users/${userId}/orders`),
+  createOrder: (data) => fetch('/orders', { method: 'POST', body: data }),
+};
+
+// BAD: Mocking requires conditional logic inside the mock
+const api = {
+  fetch: (endpoint, options) => fetch(endpoint, options),
+};
+```
+
+The SDK approach means:
+- Each mock returns one specific shape
+- No conditional logic in test setup
+- Easier to see which endpoints a test exercises
+- Type safety per endpoint

common/engineering/tdd/refactoring.md

@@ -0,0 +1,10 @@
+# Refactor Candidates
+
+After TDD cycle, look for:
+
+- **Duplication** → Extract function/class
+- **Long methods** → Break into private helpers (keep tests on public interface)
+- **Shallow modules** → Combine or deepen
+- **Feature envy** → Move logic to where data lives
+- **Primitive obsession** → Introduce value objects
+- **Existing code** the new code reveals as problematic

common/engineering/tdd/tests.md

@@ -0,0 +1,61 @@
+# Good and Bad Tests
+
+## Good Tests
+
+**Integration-style**: Test through real interfaces, not mocks of internal parts.
+
+```typescript
+// GOOD: Tests observable behavior
+test("user can checkout with valid cart", async () => {
+  const cart = createCart();
+  cart.add(product);
+  const result = await checkout(cart, paymentMethod);
+  expect(result.status).toBe("confirmed");
+});
+```
+
+Characteristics:
+
+- Tests behavior users/callers care about
+- Uses public API only
+- Survives internal refactors
+- Describes WHAT, not HOW
+- One logical assertion per test
+
+## Bad Tests
+
+**Implementation-detail tests**: Coupled to internal structure.
+
+```typescript
+// BAD: Tests implementation details
+test("checkout calls paymentService.process", async () => {
+  const mockPayment = jest.mock(paymentService);
+  await checkout(cart, payment);
+  expect(mockPayment.process).toHaveBeenCalledWith(cart.total);
+});
+```
+
+Red flags:
+
+- Mocking internal collaborators
+- Testing private methods
+- Asserting on call counts/order
+- Test breaks when refactoring without behavior change
+- Test name describes HOW not WHAT
+- Verifying through external means instead of interface
+
+```typescript
+// BAD: Bypasses interface to verify
+test("createUser saves to database", async () => {
+  await createUser({ name: "Alice" });
+  const row = await db.query("SELECT * FROM users WHERE name = ?", ["Alice"]);
+  expect(row).toBeDefined();
+});
+
+// GOOD: Verifies through interface
+test("createUser makes user retrievable", async () => {
+  const user = await createUser({ name: "Alice" });
+  const retrieved = await getUser(user.id);
+  expect(retrieved.name).toBe("Alice");
+});
+```

common/engineering/to-issues/SKILL.md

@@ -0,0 +1,84 @@
+---
+name: to-issues
+description: Break a plan, spec, or PRD into independently-grabbable issues on the project issue tracker using tracer-bullet vertical slices.
+disable-model-invocation: true
+---
+
+# To Issues
+
+Break a plan into independently-grabbable issues using vertical slices (tracer bullets).
+
+The issue tracker and triage label vocabulary should have been provided to you — run `/setup-matt-pocock-skills` if not.
+
+## Process
+
+### 1. Gather context
+
+Work from whatever is already in the conversation context. If the user passes an issue reference (issue number, URL, or path) as an argument, fetch it from the issue tracker and read its full body and comments.
+
+### 2. Explore the codebase (optional)
+
+If you have not already explored the codebase, do so to understand the current state of the code. Issue titles and descriptions should use the project's domain glossary vocabulary, and respect ADRs in the area you're touching.
+
+Look for opportunities to prefactor the code to make the implementation easier. "Make the change easy, then make the easy change."
+
+### 3. Draft vertical slices
+
+Break the plan into **tracer bullet** issues. Each issue is a thin vertical slice that cuts through ALL integration layers end-to-end, NOT a horizontal slice of one layer.
+
+<vertical-slice-rules>
+
+- Each slice delivers a narrow but COMPLETE path through every layer (schema, API, UI, tests)
+- A completed slice is demoable or verifiable on its own
+- Any prefactoring should be done first
+
+</vertical-slice-rules>
+
+### 4. Quiz the user
+
+Present the proposed breakdown as a numbered list. For each slice, show:
+
+- **Title**: short descriptive name
+- **Blocked by**: which other slices (if any) must complete first
+- **User stories covered**: which user stories this addresses (if the source material has them)
+
+Ask the user:
+
+- Does the granularity feel right? (too coarse / too fine)
+- Are the dependency relationships correct?
+- Should any slices be merged or split further?
+
+Iterate until the user approves the breakdown.
+
+### 5. Publish the issues to the issue tracker
+
+For each approved slice, publish a new issue to the issue tracker. Use the issue body template below. These issues are considered ready for AFK agents, so publish them with the correct triage label unless instructed otherwise.
+
+Publish issues in dependency order (blockers first) so you can reference real issue identifiers in the "Blocked by" field.
+
+<issue-template>
+## Parent
+
+A reference to the parent issue on the issue tracker (if the source was an existing issue, otherwise omit this section).
+
+## What to build
+
+A concise description of this vertical slice. Describe the end-to-end behavior, not layer-by-layer implementation.
+
+Avoid specific file paths or code snippets — they go stale fast. Exception: if a prototype produced a snippet that encodes a decision more precisely than prose can (state machine, reducer, schema, type shape), inline it here and note briefly that it came from a prototype. Trim to the decision-rich parts — not a working demo, just the important bits.
+
+## Acceptance criteria
+
+- [ ] Criterion 1
+- [ ] Criterion 2
+- [ ] Criterion 3
+
+## Blocked by
+
+- A reference to the blocking ticket (if any)
+
+Or "None - can start immediately" if no blockers.
+
+</issue-template>
+
+Do NOT close or modify any parent issue.

common/engineering/to-prd/SKILL.md

@@ -0,0 +1,75 @@
+---
+name: to-prd
+description: Turn the current conversation into a PRD and publish it to the project issue tracker — no interview, just synthesis of what you've already discussed.
+disable-model-invocation: true
+---
+
+This skill takes the current conversation context and codebase understanding and produces a PRD. Do NOT interview the user — just synthesize what you already know.
+
+The issue tracker and triage label vocabulary should have been provided to you — run `/setup-matt-pocock-skills` if not.
+
+## Process
+
+1. Explore the repo to understand the current state of the codebase, if you haven't already. Use the project's domain glossary vocabulary throughout the PRD, and respect any ADRs in the area you're touching.
+
+2. Sketch out the seams at which you're going to test the feature. Existing seams should be preferred to new ones. Use the highest seam possible. If new seams are needed, propose them at the highest point you can. The fewer seams across the codebase, the better - the ideal number is one.
+
+Check with the user that these seams match their expectations.
+
+3. Write the PRD using the template below, then publish it to the project issue tracker. Apply the `ready-for-agent` triage label - no need for additional triage.
+
+<prd-template>
+
+## Problem Statement
+
+The problem that the user is facing, from the user's perspective.
+
+## Solution
+
+The solution to the problem, from the user's perspective.
+
+## User Stories
+
+A LONG, numbered list of user stories. Each user story should be in the format of:
+
+1. As an <actor>, I want a <feature>, so that <benefit>
+
+<user-story-example>
+1. As a mobile bank customer, I want to see balance on my accounts, so that I can make better informed decisions about my spending
+</user-story-example>
+
+This list of user stories should be extremely extensive and cover all aspects of the feature.
+
+## Implementation Decisions
+
+A list of implementation decisions that were made. This can include:
+
+- The modules that will be built/modified
+- The interfaces of those modules that will be modified
+- Technical clarifications from the developer
+- Architectural decisions
+- Schema changes
+- API contracts
+- Specific interactions
+
+Do NOT include specific file paths or code snippets. They may end up being outdated very quickly.
+
+Exception: if a prototype produced a snippet that encodes a decision more precisely than prose can (state machine, reducer, schema, type shape), inline it within the relevant decision and note briefly that it came from a prototype. Trim to the decision-rich parts — not a working demo, just the important bits.
+
+## Testing Decisions
+
+A list of testing decisions that were made. Include:
+
+- A description of what makes a good test (only test external behavior, not implementation details)
+- Which modules will be tested
+- Prior art for the tests (i.e. similar types of tests in the codebase)
+
+## Out of Scope
+
+A description of the things that are out of scope for this PRD.
+
+## Further Notes
+
+Any further notes about the feature.
+
+</prd-template>

common/engineering/triage/AGENT-BRIEF.md

@@ -0,0 +1,207 @@
+# Writing Agent Briefs
+
+An agent brief is a structured comment posted on a GitHub issue or PR when it moves to `ready-for-agent`. It is the authoritative specification that an AFK agent will work from. The original body and discussion are context — the agent brief is the contract.
+
+The brief states **what the agent should do**, which stretches to both surfaces: for an issue, that's building the change from nothing; for a PR, it's what's left to do *to the existing diff* — finish it, close gaps, address review points. Same principles either way; the PR example below shows the difference.
+
+## Principles
+
+### Durability over precision
+
+The issue may sit in `ready-for-agent` for days or weeks. The codebase will change in the meantime. Write the brief so it stays useful even as files are renamed, moved, or refactored.
+
+- **Do** describe interfaces, types, and behavioral contracts
+- **Do** name specific types, function signatures, or config shapes that the agent should look for or modify
+- **Don't** reference file paths — they go stale
+- **Don't** reference line numbers
+- **Don't** assume the current implementation structure will remain the same
+
+### Behavioral, not procedural
+
+Describe **what** the system should do, not **how** to implement it. The agent will explore the codebase fresh and make its own implementation decisions.
+
+- **Good:** "The `SkillConfig` type should accept an optional `schedule` field of type `CronExpression`"
+- **Bad:** "Open src/types/skill.ts and add a schedule field on line 42"
+- **Good:** "When a user runs `/triage` with no arguments, they should see a summary of issues needing attention"
+- **Bad:** "Add a switch statement in the main handler function"
+
+### Complete acceptance criteria
+
+The agent needs to know when it's done. Every agent brief must have concrete, testable acceptance criteria. Each criterion should be independently verifiable.
+
+- **Good:** "Running `gh issue list --label needs-triage` returns issues that have been through initial classification"
+- **Bad:** "Triage should work correctly"
+
+### Explicit scope boundaries
+
+State what is out of scope. This prevents the agent from gold-plating or making assumptions about adjacent features.
+
+## Template
+
+```markdown
+## Agent Brief
+
+**Category:** bug / enhancement
+**Summary:** one-line description of what needs to happen
+
+**Current behavior:**
+Describe what happens now. For bugs, this is the broken behavior.
+For enhancements, this is the status quo the feature builds on.
+
+**Desired behavior:**
+Describe what should happen after the agent's work is complete.
+Be specific about edge cases and error conditions.
+
+**Key interfaces:**
+- `TypeName` — what needs to change and why
+- `functionName()` return type — what it currently returns vs what it should return
+- Config shape — any new configuration options needed
+
+**Acceptance criteria:**
+- [ ] Specific, testable criterion 1
+- [ ] Specific, testable criterion 2
+- [ ] Specific, testable criterion 3
+
+**Out of scope:**
+- Thing that should NOT be changed or addressed in this issue
+- Adjacent feature that might seem related but is separate
+```
+
+## Examples
+
+### Good agent brief (bug)
+
+```markdown
+## Agent Brief
+
+**Category:** bug
+**Summary:** Skill description truncation drops mid-word, producing broken output
+
+**Current behavior:**
+When a skill description exceeds 1024 characters, it is truncated at exactly
+1024 characters regardless of word boundaries. This produces descriptions
+that end mid-word (e.g. "Use when the user wants to confi").
+
+**Desired behavior:**
+Truncation should break at the last word boundary before 1024 characters
+and append "..." to indicate truncation.
+
+**Key interfaces:**
+- The `SkillMetadata` type's `description` field — no type change needed,
+  but the validation/processing logic that populates it needs to respect
+  word boundaries
+- Any function that reads SKILL.md frontmatter and extracts the description
+
+**Acceptance criteria:**
+- [ ] Descriptions under 1024 chars are unchanged
+- [ ] Descriptions over 1024 chars are truncated at the last word boundary
+      before 1024 chars
+- [ ] Truncated descriptions end with "..."
+- [ ] The total length including "..." does not exceed 1024 chars
+
+**Out of scope:**
+- Changing the 1024 char limit itself
+- Multi-line description support
+```
+
+### Good agent brief (enhancement)
+
+```markdown
+## Agent Brief
+
+**Category:** enhancement
+**Summary:** Add `.out-of-scope/` directory support for tracking rejected feature requests
+
+**Current behavior:**
+When a feature request is rejected, the issue is closed with a `wontfix` label
+and a comment. There is no persistent record of the decision or reasoning.
+Future similar requests require the maintainer to recall or search for the
+prior discussion.
+
+**Desired behavior:**
+Rejected feature requests should be documented in `.out-of-scope/<concept>.md`
+files that capture the decision, reasoning, and links to all issues that
+requested the feature. When triaging new issues, these files should be
+checked for matches.
+
+**Key interfaces:**
+- Markdown file format in `.out-of-scope/` — each file should have a
+  `# Concept Name` heading, a `**Decision:**` line, a `**Reason:**` line,
+  and a `**Prior requests:**` list with issue links
+- The triage workflow should read all `.out-of-scope/*.md` files early
+  and match incoming issues against them by concept similarity
+
+**Acceptance criteria:**
+- [ ] Closing a feature as wontfix creates/updates a file in `.out-of-scope/`
+- [ ] The file includes the decision, reasoning, and link to the closed issue
+- [ ] If a matching `.out-of-scope/` file already exists, the new issue is
+      appended to its "Prior requests" list rather than creating a duplicate
+- [ ] During triage, existing `.out-of-scope/` files are checked and surfaced
+      when a new issue matches a prior rejection
+
+**Out of scope:**
+- Automated matching (human confirms the match)
+- Reopening previously rejected features
+- Bug reports (only enhancement rejections go to `.out-of-scope/`)
+```
+
+### Good agent brief (PR)
+
+For a PR, "Current behavior" describes the state of the diff, and the brief asks the agent to finish or fix it rather than build from scratch.
+
+```markdown
+## Agent Brief
+
+**Category:** enhancement
+**Summary:** Finish the contributor's `--json` output flag for `triage list`
+
+**Current behavior:**
+The PR adds a `--json` flag that serializes the issue list to JSON. The happy
+path works and the diff matches the project's command structure. Two gaps
+remain: errors are still printed as human text (not JSON), and the new flag has
+no test coverage.
+
+**Desired behavior:**
+With `--json`, all output — including errors — is well-formed JSON on stdout,
+and the command's exit codes are unchanged. The existing human-readable output
+is untouched when the flag is absent.
+
+**Key interfaces:**
+- The command's error path should emit `{ "error": string }` under `--json`
+  instead of the plain-text error
+- Reuse the existing serializer the PR already added; don't introduce a second
+
+**Acceptance criteria:**
+- [ ] `triage list --json` emits valid JSON for both success and error cases
+- [ ] Exit codes match the non-JSON command
+- [ ] A test covers the `--json` success output and one error case
+- [ ] Default (non-JSON) output is byte-for-byte unchanged
+
+**Out of scope:**
+- Adding `--json` to any other command
+- Changing the JSON shape of the success payload the PR already defined
+```
+
+### Bad agent brief
+
+```markdown
+## Agent Brief
+
+**Summary:** Fix the triage bug
+
+**What to do:**
+The triage thing is broken. Look at the main file and fix it.
+The function around line 150 has the issue.
+
+**Files to change:**
+- src/triage/handler.ts (line 150)
+- src/types.ts (line 42)
+```
+
+This is bad because:
+- No category
+- Vague description ("the triage thing is broken")
+- References file paths and line numbers that will go stale
+- No acceptance criteria
+- No scope boundaries
+- No description of current vs desired behavior

common/engineering/triage/OUT-OF-SCOPE.md

@@ -0,0 +1,105 @@
+# Out-of-Scope Knowledge Base
+
+The `.out-of-scope/` directory in a repo stores persistent records of rejected feature requests. It serves two purposes:
+
+1. **Institutional memory** — why a feature was rejected, so the reasoning isn't lost when the issue is closed
+2. **Deduplication** — when a new issue comes in that matches a prior rejection, the skill can surface the previous decision instead of re-litigating it
+
+## Directory structure
+
+```
+.out-of-scope/
+├── dark-mode.md
+├── plugin-system.md
+└── graphql-api.md
+```
+
+One file per **concept**, not per issue. Multiple issues requesting the same thing are grouped under one file.
+
+## File format
+
+The file should be written in a relaxed, readable style — more like a short design document than a database entry. Use paragraphs, code samples, and examples to make the reasoning clear and useful to someone encountering it for the first time.
+
+```markdown
+# Dark Mode
+
+This project does not support dark mode or user-facing theming.
+
+## Why this is out of scope
+
+The rendering pipeline assumes a single color palette defined in
+`ThemeConfig`. Supporting multiple themes would require:
+
+- A theme context provider wrapping the entire component tree
+- Per-component theme-aware style resolution
+- A persistence layer for user theme preferences
+
+This is a significant architectural change that doesn't align with the
+project's focus on content authoring. Theming is a concern for downstream
+consumers who embed or redistribute the output.
+
+```ts
+// The current ThemeConfig interface is not designed for runtime switching:
+interface ThemeConfig {
+  colors: ColorPalette; // single palette, resolved at build time
+  fonts: FontStack;
+}
+```
+
+## Prior requests
+
+- #42 — "Add dark mode support"
+- #87 — "Night theme for accessibility"
+- #134 — "Dark theme option"
+```
+
+### Naming the file
+
+Use a short, descriptive kebab-case name for the concept: `dark-mode.md`, `plugin-system.md`, `graphql-api.md`. The name should be recognizable enough that someone browsing the directory understands what was rejected without opening the file.
+
+### Writing the reason
+
+The reason should be substantive — not "we don't want this" but why. Good reasons reference:
+
+- Project scope or philosophy ("This project focuses on X; theming is a downstream concern")
+- Technical constraints ("Supporting this would require Y, which conflicts with our Z architecture")
+- Strategic decisions ("We chose to use A instead of B because...")
+
+The reason should be durable. Avoid referencing temporary circumstances ("we're too busy right now") — those aren't real rejections, they're deferrals.
+
+## When to check `.out-of-scope/`
+
+During triage (Step 1: Gather context), read all files in `.out-of-scope/`. When evaluating a new issue:
+
+- Check if the request matches an existing out-of-scope concept
+- Matching is by concept similarity, not keyword — "night theme" matches `dark-mode.md`
+- If there's a match, surface it to the maintainer: "This is similar to `.out-of-scope/dark-mode.md` — we rejected this before because [reason]. Do you still feel the same way?"
+
+The maintainer may:
+
+- **Confirm** — the new issue gets added to the existing file's "Prior requests" list, then closed
+- **Reconsider** — the out-of-scope file gets deleted or updated, and the issue proceeds through normal triage
+- **Disagree** — the issues are related but distinct, proceed with normal triage
+
+## When to write to `.out-of-scope/`
+
+Only when an **enhancement** (not a bug) is *rejected* as `wontfix`. This applies to enhancement PRs exactly as it does to issues — a rejected PR is recorded here so the same request doesn't return as fresh code.
+
+Do **not** write here when something is closed as `wontfix` because it's **already implemented**. That's a built feature, not a rejected one; recording it would poison the dedup checks with false rejections. Instead, the closing comment points to where the feature already lives.
+
+The flow:
+
+1. Maintainer decides a feature request is out of scope
+2. Check if a matching `.out-of-scope/` file already exists
+3. If yes: append the new issue to the "Prior requests" list
+4. If no: create a new file with the concept name, decision, reason, and first prior request
+5. Post a comment on the issue explaining the decision and mentioning the `.out-of-scope/` file
+6. Close the issue with the `wontfix` label
+
+## Updating or removing out-of-scope files
+
+If the maintainer changes their mind about a previously rejected concept:
+
+- Delete the `.out-of-scope/` file
+- The skill does not need to reopen old issues — they're historical records
+- The new issue that triggered the reconsideration proceeds through normal triage

common/engineering/triage/SKILL.md

@@ -0,0 +1,112 @@
+---
+name: triage
+description: Move issues and external PRs through a state machine of triage roles — categorise, verify, grill if needed, and write agent-ready briefs.
+disable-model-invocation: true
+---
+
+# Triage
+
+Move issues on the project issue tracker through a small state machine of triage roles.
+
+If this repo treats external pull requests as a request surface (see the issue-tracker config), triage covers them too: **a PR is an issue with attached code** — same roles, same states, same machine, with a few deltas marked "for a PR" below. Resolve a bare `#42` to an issue or PR per the tracker config.
+
+Every comment or issue posted to the issue tracker during triage **must** start with this disclaimer:
+
+```
+> *This was generated by AI during triage.*
+```
+
+## Reference docs
+
+- [AGENT-BRIEF.md](AGENT-BRIEF.md) — how to write durable agent briefs
+- [OUT-OF-SCOPE.md](OUT-OF-SCOPE.md) — how the `.out-of-scope/` knowledge base works
+
+## Roles
+
+Two **category** roles:
+
+- `bug` — something is broken
+- `enhancement` — new feature or improvement
+
+Five **state** roles:
+
+- `needs-triage` — maintainer needs to evaluate
+- `needs-info` — waiting on reporter for more information
+- `ready-for-agent` — fully specified, ready for an AFK agent
+- `ready-for-human` — needs human implementation
+- `wontfix` — will not be actioned
+
+For a PR, the same states read against the attached code: `ready-for-agent` means a brief is attached and an agent should take the next step on the diff; `ready-for-human` means it's ready for a human to merge.
+
+Every triaged issue should carry exactly one category role and one state role. If state roles conflict, flag it and ask the maintainer before doing anything else.
+
+These are canonical role names — the actual label strings used in the issue tracker may differ. The mapping should have been provided to you - run `/setup-matt-pocock-skills` if not.
+
+State transitions: an unlabeled issue normally goes to `needs-triage` first; from there it moves to `needs-info`, `ready-for-agent`, `ready-for-human`, or `wontfix`. `needs-info` returns to `needs-triage` once the reporter replies. The maintainer can override at any time — flag transitions that look unusual and ask before proceeding.
+
+## Invocation
+
+The maintainer invokes `/triage` and describes what they want in natural language. Interpret the request and act. Examples:
+
+- "Show me anything that needs my attention"
+- "Let's look at #42" (issue or PR)
+- "Move #42 to ready-for-agent"
+- "What's ready for agents to pick up?"
+
+## Show what needs attention
+
+Query the issue tracker and present three buckets, oldest first:
+
+1. **Unlabeled** — never triaged.
+2. **`needs-triage`** — evaluation in progress.
+3. **`needs-info` with reporter activity since the last triage notes** — needs re-evaluation.
+
+When PRs are in scope, include external PRs in these buckets and tag each line `[PR]` or `[issue]`. Discovery surfaces only *external* PRs (the tracker config defines who counts as external) — a collaborator's in-flight PR is not triage work. This filter is discovery-only; an explicitly named PR is always triaged regardless of author.
+
+Show counts and a one-line summary per item. Let the maintainer pick.
+
+## Triage a specific issue or PR
+
+1. **Gather context.** Read the full issue or PR (body, comments, labels, author, dates; for a PR, the diff too). Parse any prior triage notes so you don't re-ask resolved questions. Explore the codebase using the project's domain glossary, respecting ADRs in the area. Run two checks against the codebase: (a) **redundancy** — search for an existing implementation of the requested behavior by domain concept (not just the request's wording), and report where you looked. If found, it's an already-implemented `wontfix` (step 5). (b) **prior rejection** — read `.out-of-scope/*.md` and surface any that resembles this request.
+
+2. **Recommend.** Tell the maintainer your category and state recommendation with reasoning, plus a brief codebase summary relevant to the request — including whether it's already implemented. Wait for direction.
+
+3. **Verify the claim.** Before any grilling, check that the claim holds up. For a bug, reproduce it from the reporter's steps. For a PR, confirm the diff does what it claims — check it out, run the relevant tests or commands. Report what happened: confirmed (with code path), failed, or insufficient detail (a strong `needs-info` signal). A confirmed verification makes a much stronger agent brief.
+
+4. **Grill (if needed).** If the request needs fleshing out, run the `/grilling` and `/domain-modeling` skills together — grill it into shape one question at a time, sharpening domain terms and updating `CONTEXT.md`/ADRs inline as decisions land.
+
+5. **Apply the outcome:**
+   - `ready-for-agent` — post an agent brief comment ([AGENT-BRIEF.md](AGENT-BRIEF.md)).
+   - `ready-for-human` — same structure as an agent brief, but note why it can't be delegated (judgment calls, external access, design decisions, manual testing).
+   - `needs-info` — post triage notes (template below).
+   - `wontfix` — close, with the comment depending on *why*:
+     - **Already implemented** — the change already exists in the codebase. Point to where it lives; do **not** write to `.out-of-scope/` (that KB is for *rejected* requests, not built ones).
+     - **Rejected (bug)** — polite explanation, then close.
+     - **Rejected (enhancement)** — write to `.out-of-scope/`, link to it from a comment, then close ([OUT-OF-SCOPE.md](OUT-OF-SCOPE.md)).
+   - `needs-triage` — apply the role. Optional comment if there's partial progress.
+
+## Quick state override
+
+If the maintainer says "move #42 to ready-for-agent", trust them and apply the role directly. Confirm what you're about to do (role changes, comment, close), then act. Skip grilling. If moving to `ready-for-agent` without a grilling session, ask whether they want to write an agent brief.
+
+## Needs-info template
+
+```markdown
+## Triage Notes
+
+**What we've established so far:**
+
+- point 1
+- point 2
+
+**What we still need from you (@reporter):**
+
+- question 1
+- question 2
+```
+
+Capture everything resolved during grilling under "established so far" so the work isn't lost. Questions must be specific and actionable, not "please provide more info".
+
+## Resuming a previous session
+
+If prior triage notes exist on the issue or PR, read them, check whether the reporter has answered any outstanding questions, and present an updated picture before continuing. Don't re-ask resolved questions.