feat(watchers): Integrate chokidar-based Node watcher, expose awaitWriteFinish options, and update docs/tests

ts/watchers/interfaces.ts

@@ -28,6 +28,12 @@ export interface IWatcherOptions {
   followSymlinks: boolean;
   /** Debounce time in ms - events for the same file within this window are coalesced */
   debounceMs: number;
+  /** Whether to wait for writes to stabilize before emitting events */
+  awaitWriteFinish?: boolean;
+  /** How long file size must remain constant before emitting event (ms) */
+  stabilityThreshold?: number;
+  /** How often to poll file size during write detection (ms) */
+  pollInterval?: number;
 }
 
 /**