fix(hooks): replace lib symlinks with real file copies (#82)

## Summary

- Replace `lib` symlinks in all 4 editor plugin `hooks/prevent/`
directories with real file copies
- The relative symlink (`../../../shared/prevent/lib`) breaks when the
plugin cache is rebuilt on `/clear` or `/reload-plugins` — the flat
cache directory structure can't resolve it, causing
`ModuleNotFoundError: No module named 'lib'`
- `plugins/shared/prevent/lib/` remains as the canonical source;
`bump-version.sh` now syncs it to all plugins at release time
- Updated docs (CONTRIBUTING.md, architecture guide, cursor README) and
codex install script to reflect the new approach

Fixes: Zendesk #27286

## Test plan

- [ ] Install plugin fresh via marketplace — hooks should work
- [ ] Run `/clear` — hooks should still work (no `ModuleNotFoundError`)
- [ ] Run `/reload-plugins` — hooks should still work
- [ ] Verify `bump-version.sh --dry-run` shows the new sync step
- [ ] Verify codex `install.sh` still works with updated `SHARED_LIB`
path

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: mdediana

CONTRIBUTING.md

@@ -20,8 +20,8 @@ mc-agent-toolkit/
 │   └── remediation/
 │
 ├── plugins/
-│   ├── shared/                          # Platform-agnostic hook logic
-│   │   └── prevent/lib/                 # Business logic (symlinked by editor plugins)
+│   ├── shared/                          # Canonical hook logic (source of truth)
+│   │   └── prevent/lib/                 # Business logic (copied into each editor plugin's hooks/prevent/lib/)
 │   │
 │   ├── claude-code/                     # Unified mc-agent-toolkit plugin
 │   │   ├── .claude-plugin/plugin.json
@@ -50,7 +50,7 @@ mc-agent-toolkit/
 └── SECURITY.md
 ```
 
-Plugins reference skills via symlinks so that skills are authored once and shared across all editor plugins. Shared hook logic in `plugins/shared/<skill>/lib/` is also symlinked into editor-specific adapter directories.
+Plugins reference skills via symlinks so that skills are authored once and shared across all editor plugins. Shared hook logic lives in `plugins/shared/<skill>/lib/` as the canonical source and is **copied** (not symlinked) into each editor plugin's `hooks/<skill>/lib/` directory. The `bump-version.sh` script syncs these copies automatically at release time. If you edit shared hook logic, edit it in `plugins/shared/` and run `./scripts/bump-version.sh` to propagate.
 
 ## Adding a new skill
 
@@ -192,7 +192,8 @@ Setup and agent-routing skills are exempt from this rule. Setup skills are invok
 - Include a clear description of what the skill/plugin does and when it should activate.
 - For new skills: include example prompts that should trigger the skill.
 - For bug fixes: describe the incorrect behavior and how to reproduce.
-- Ensure symlinks are relative and resolve correctly (CI will verify this).
+- Ensure skill symlinks are relative and resolve correctly (CI will verify this).
+- If you changed files in `plugins/shared/prevent/lib/`, run `./scripts/bump-version.sh` to sync copies to all editor plugins.
 - Run `git log --follow` on any moved files to confirm history is preserved.
 
 ## Version bumping

docs/plugin-architecture-guide.md

@@ -95,7 +95,7 @@ mc-agent-toolkit/
 │   │   ├── .claude-plugin/plugin.json
 │   │   ├── .mcp.json
 │   │   ├── hooks/
-│   │   │   └── prevent/                 # Thin adapters → plugins/shared/prevent/lib/
+│   │   │   └── prevent/                 # Adapters + lib/ (copied from plugins/shared/prevent/lib/)
 │   │   ├── skills/                      # One symlink per skill → ../../../skills/<name>
 │   │   └── commands/
 │   │       ├── prevent/