feat(plugins): make CCAM installable straight from a Claude Code plugin

Adds a root `ccam` plugin (`.claude-plugin/plugin.json`, `"source": "./"`) so
`/plugin marketplace add` + `/plugin install ccam@...` is enough on a machine
with nothing but Claude Code: no clone, no npm run setup, no manual npm start.

- scripts/plugin-bootstrap.js: SessionStart hook. Fast-path exit, Node >=22.5
  gate (node:sqlite), mkdir lock with stale reclaim, deps installed into
  ~/.claude/agent-dashboard/runtime/ (never the plugin cache), legacy
  checkout-hook cleanup (backed up), ~/.local/bin/ccam launcher, eager UI
  build so client routes like /run work immediately, detached server spawn.
- scripts/plugin-open.js, scripts/plugin-doctor.js: /ccam-open, /ccam-doctor.
- server/index.js: DASHBOARD_CLIENT_DIST override (plugin cache is read-only).
- mcp/build/ is committed (plugin MCP servers start before any bootstrap could
  build them) and kept honest by scripts/check-mcp-build.js (content hash,
  not mtime), enforced by pre-commit when mcp/src changes.
- plugins/ccam-dashboard/.mcp.json moved under plugins/ccam/ with a working
  ${CLAUDE_PLUGIN_ROOT} path (the old relative path never resolved from a
  marketplace-cached subdir).
- Docs: README, INSTALL, SETUP, ARCHITECTURE, CLAUDE.md, docs/PLUGINS.md,
  docs/MCP.md, docs/CLI.md, docs/HOOKS.md.

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

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

mcp/package-lock.json

@@ -27,31 +27,35 @@
     },
     "..": {
       "name": "agent-dashboard",
-      "version": "1.1.1",
-      "license": "MIT",
+      "version": "1.4.6",
+      "hasInstallScript": true,
+      "license": "UNLICENSED",
       "dependencies": {
         "adm-zip": "^0.5.16",
         "cors": "^2.8.5",
+        "cross-spawn": "^7.0.6",
         "express": "^4.21.2",
         "multer": "^2.0.0",
+        "redoc": "^2.5.3",
         "swagger-ui-express": "^5.0.1",
         "tar": "^7.4.3",
         "uuid": "^11.1.0",
         "web-push": "^3.6.7",
         "ws": "^8.18.0"
       },
+      "bin": {
+        "ccam": "bin/ccam.js"
+      },
       "devDependencies": {
         "concurrently": "^9.1.2",
+        "js-yaml": "^4.1.0",
         "prettier": "^3.8.1"
       },
       "engines": {
-        "node": ">=18.0.0"
-      },
-      "funding": {
-        "url": "https://github.com/sponsors/hoangsonww"
+        "node": ">=20.0.0"
       },
       "optionalDependencies": {
-        "better-sqlite3": "^11.7.0"
+        "better-sqlite3": "^12.0.0"
       }
     },
     "node_modules/@esbuild/aix-ppc64": {