refactor(fish): use command -q, group aliases, add mise config

- Replace test -x / command -qv with command -q for consistency
- Move mise/direnv/zoxide/fzf init to top of interactive block
- Group related aliases into if blocks
- Remove redundant vim/vi->v aliases (nvim handles EDITOR)
- Fix fabric alias: fabric-ai -> fabric
- Add config/mise/config.toml with tool definitions
- Swap realpath/nvim check order in script/v

config/mise/config.toml

@@ -0,0 +1,23 @@
+[settings]
+experimental = true
+
+[tools]
+age = "latest"
+bun = "latest"
+"cargo:cargo-llvm-cov" = "latest"
+codex = "latest"
+copilot-cli = "latest"
+"github:ZinoKader/portal" = "latest"
+"github:danielmiessler/fabric" = "latest"
+"github:mrusme/reader" = "latest"
+"github:ulyssa/iamb" = "latest"
+herdr = "latest"
+neovim = "latest"
+node = "latest"
+"npm:@earendil-works/pi-coding-agent" = "latest"
+"npm:mermaid-cli" = "latest"
+"npm:pi-acp" = "latest"
+opencode = "latest"
+pi = "latest"
+tree-sitter = "latest"
+worktrunk = "latest"