feat(#789): elevate CodeBuddy — slash commands (#830)

* feat(#789): elevate CodeBuddy — emit slash commands (+ document subagent/MCP scope)

Emit a CodeBuddy slash-command surface so GSD workflows appear in the
'/' menu, reaching parity with other elevated runtimes.

- Add convertClaudeCommandToCodebuddyCommand and register a commands/
  artifact kind for the codebuddy runtime (commands/gsd-<name>.md),
  consistent with the Cursor (#785) and Augment (#790) commands surfaces.
- Mark emitted skills user-invocable:false so the commands surface is the
  sole '/' entry point (no duplicate /gsd-* entries); skills stay
  model-invocable. CodeBuddy's SKILL.md supports this field.
- Normalize $HOME/.codebuddy (bare + slash) path forms in runtime
  rewrites so --config-dir/local installs don't leak the default home.
- Report installed commands/ count on install; uninstall prunes gsd-*
  commands while preserving user-owned commands.

Scope: subagents (~/.codebuddy/agents/) are already emitted by the
generic agents block (unchanged); no mcp.json is written (gsd ships no
MCP server, and CodeBuddy's mcp.json registers only external servers).

Closes #789

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* chore(#789): set changeset pr number to 830

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

docs/ARCHITECTURE.md

@@ -808,7 +808,7 @@ The migration-specific ownership and source snapshots live in
 | Trae | `~/.trae` | `./.trae` | `skills/gsd-*/SKILL.md` | `agents/gsd-*.md` | Rule references under `rules/`; no GSD hooks |
 | Qwen Code | `~/.qwen` | `./.qwen` | `skills/gsd-*/SKILL.md` | `agents/gsd-*.md` | Common GSD settings and hook entries where supported |
 | Hermes Agent | `~/.hermes` | `./.hermes` | `skills/gsd/DESCRIPTION.md` plus `skills/gsd/gsd-*/SKILL.md` | `agents/gsd-*.md` | Common GSD settings and hook entries where supported |
-| CodeBuddy | `~/.codebuddy` | `./.codebuddy` | `skills/gsd-*/SKILL.md` | `agents/gsd-*.md` | Common GSD settings and hook entries where supported |
+| CodeBuddy | `~/.codebuddy` | `./.codebuddy` | `skills/gsd-*/SKILL.md` (`user-invocable: false`) | `agents/gsd-*.md` | `/gsd-*` slash commands under `commands/`; common GSD settings and hook entries where supported |
 | Cline | `~/.cline` | project root | `.clinerules` | Rules only | No GSD hooks or statusline |
 
 ### Upstream Contract Sources

docs/FEATURES.md

@@ -2290,7 +2290,7 @@ Test suite that scans all agent, workflow, and command files for embedded inject
 
 **Requirements:**
 - REQ-CLINE-02: Cline install MUST write `.clinerules` to `~/.cline/` (global) or `./.cline/` (local). No custom slash commands — rules-based integration only. Flag: `--cline`.
-- REQ-CODEBUDDY-01: CodeBuddy install MUST deploy skills to `~/.codebuddy/skills/gsd-*/SKILL.md`. Flag: `--codebuddy`.
+- REQ-CODEBUDDY-01: CodeBuddy install MUST deploy skills to `~/.codebuddy/skills/gsd-*/SKILL.md` (emitted `user-invocable: false`), `/gsd-*` slash commands to `~/.codebuddy/commands/gsd-*.md`, and subagents to `~/.codebuddy/agents/gsd-*.md`. The commands surface is the sole `/` menu entry point. No `mcp.json` is written (gsd ships no MCP server). Flag: `--codebuddy`.
 - REQ-QWEN-01: Qwen Code install MUST deploy skills to `~/.qwen/skills/gsd-*/SKILL.md`, following the open standard used by Claude Code 2.1.88+. `QWEN_CONFIG_DIR` env var overrides the default path. Flag: `--qwen`.
 
 **Runtime summary:**

docs/USER-GUIDE.md

@@ -746,6 +746,8 @@ npx @opengsd/gsd-core --cline --local    # this project only
 npx @opengsd/gsd-core --codebuddy --global
 ```
 
+GSD installs four surfaces for CodeBuddy: `/gsd-*` slash commands in `~/.codebuddy/commands/`, subagents in `~/.codebuddy/agents/`, model-invocable skills in `~/.codebuddy/skills/`, and `settings.json` hooks. The skills are emitted with `user-invocable: false` so the slash commands are the single `/` menu surface (no duplicate entries).
+
 ### Installing for Qwen Code
 
 ```bash

docs/how-to/install-on-your-runtime.md

@@ -281,7 +281,7 @@ directory is created for local scope.
 npx @opengsd/gsd-core@latest --codebuddy --global
 ```
 
-Skills land in `~/.codebuddy/skills/gsd-*/SKILL.md`.
+GSD installs four surfaces. Slash command definitions land in `~/.codebuddy/commands/gsd-*.md` and appear as `/gsd-help`, `/gsd-phase`, `/gsd-ship`, etc. in the `/` menu. Subagents land in `~/.codebuddy/agents/gsd-*.md`. Skills land in `~/.codebuddy/skills/gsd-*/SKILL.md` — emitted with `user-invocable: false` so they stay out of the `/` menu (the commands surface is the sole `/` entry point) and remain available for model invocation. CodeBuddy hooks are written to `settings.json`. No `mcp.json` is written: GSD ships no MCP server.
 
 ---