fix: cap watcher directories to wait-object limit

[H-Chris233]

Problem

FileWatcher passes all watched directories as handles to WaitForMultipleObjects. When the number of directories exceeds MAXIMUM_WAIT_OBJECTS (typically 64), the call fails with WAIT_FAILED. On an empty directory list, WaitForMultipleObjects with zero handles also behaves unexpectedly.

Changes

1. Cap at MAXIMUM_WAIT_OBJECTS: if the directory count exceeds the OS limit, log a warning and truncate.
2. Early exit on empty: if no directories are configured, return immediately in both Start() and WatcherThread().
3. Added warning logs for both edge cases.

Testing

• Tested with 0, 1, 64, and 65+ directories in the watch list.