refactor: migrate from shell-based sync to mise dotfiles management

- Replace sync-config/sync-script with mise.toml [dotfiles] directives
- Convert installer scripts to mise tasks (shells, desktop, theme, webapps)
- Remove config/nvim-old (deprecated neovim config)
- Add omarchy theme system with multi-app configs (btop, hyprland, kitty, foot, tmux, etc.)
- Move SSH hosts to config.d/* include pattern
- Add Tera templates for dynamic config generation (git-local, dofiles.conf)
- Update pi agent settings (0.80.10, packages list)
- Add mise tasks for pi plugin setup and nvim tooling

config/omarchy/default/neovim-vimpack.lua

@@ -0,0 +1,12 @@
+vim.pack.add({{ src = 'https://github.com/folke/tokyonight.nvim' }})
+require("tokyonight").setup({
+    style = "night",
+    transparent = true,
+    terminal_colors = true,
+    styles = {
+        sidebars = "transparent",
+        floats = "transparent",
+    },
+})
+
+vim.cmd("colorscheme tokyonight")