feat(adapters): external adapter plugin system with dynamic UI parser

- Plugin loader: install/reload/remove/reinstall external adapters
  from npm packages or local directories
- Plugin store persisted at ~/.paperclip/adapter-plugins.json
- Self-healing UI parser resolution with version caching
- UI: Adapter Manager page, dynamic loader, display registry
  with humanized names for unknown adapter types
- Dev watch: exclude adapter-plugins dir from tsx watcher
  to prevent mid-request server restarts during reinstall
- All consumer fallbacks use getAdapterLabel() for consistent display
- AdapterTypeDropdown uses controlled open state for proper close behavior
- Remove hermes-local from built-in UI (externalized to plugin)
- Add docs for external adapters and UI parser contract

ui/src/lib/queryKeys.ts

@@ -144,4 +144,7 @@ export const queryKeys = {
     dashboard: (pluginId: string) => ["plugins", pluginId, "dashboard"] as const,
     logs: (pluginId: string) => ["plugins", pluginId, "logs"] as const,
   },
+  adapters: {
+    all: ["adapters"] as const,
+  },
 };