cli: implement local→CouchDB file watching via chokidar

- Add chokidar ^4.0.0 as dependency (root package.json, runtime-package.json)
- Mark chokidar as external in vite.config.ts (not bundled, loaded at runtime)
- Implement CLIWatchAdapter.beginWatch() with chokidar:
  - ignoreInitial: true (startup files handled by mirror scan)
  - awaitWriteFinish to prevent partial-write events
  - Excludes dotfiles and .livesync/ directory at watcher level
  - Maps add/change/unlink/addDir/unlinkDir to IStorageEventWatchHandlers
  - Fatal error handler: logs clearly and releases watcher resources
- Add close() to CLIWatchAdapter, StorageEventManagerCLI for clean shutdown
- Register onUnload hook in CLIServiceModules to close watcher on shutdown

package.json

@@ -127,6 +127,7 @@
     },
     "dependencies": {
         "@aws-sdk/client-s3": "^3.808.0",
+        "chokidar": "^4.0.0",
         "@smithy/fetch-http-handler": "^5.3.10",
         "@smithy/md5-js": "^4.2.9",
         "@smithy/middleware-apply-body-checksum": "^4.3.9",