refactor: consolidate plugins into plugins/ directory

- Created plugins/ directory to centralize all plugins
- Moved projman and project-hygiene into plugins/
- Updated .mcp.json paths from ../mcp-servers/ to ../../mcp-servers/
- Updated CLAUDE.md governance section with new directory structure
- Updated README.md with new repository structure diagram
- Fixed all path references in documentation

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plugins/project-hygiene/.claude-plugin/plugin.json

@@ -0,0 +1,12 @@
+{
+  "name": "project-hygiene",
+  "version": "0.1.0",
+  "description": "Post-task cleanup hook that removes temp files, warns about unexpected root files, and manages orphaned supporting files",
+  "author": {
+    "name": "Bandit Labs",
+    "email": "dev@banditlabs.io"
+  },
+  "license": "MIT",
+  "keywords": ["cleanup", "hygiene", "automation", "hooks", "maintenance"],
+  "repository": "https://github.com/bandit-labs/project-hygiene"
+}