Refactor agent spawning and delegation check mechanisms

- Updated agent spawning from `Task()` to `Agent()` across various files to align with new standards.
- Enhanced the `code-developer` agent description to clarify its invocation context and responsibilities.
- Introduced a new `delegation-check` skill to validate command delegation prompts against agent role definitions, ensuring content separation and conflict detection.
- Established comprehensive separation rules for command delegation prompts and agent definitions, detailing ownership and conflict patterns.
- Improved documentation for command and agent design specifications to reflect the updated spawning patterns and validation processes.

codex-lens-v2/src/codexlens_search/watcher/__init__.py

@@ -0,0 +1,17 @@
+"""File watcher and incremental indexer for codexlens-search.
+
+Requires the ``watcher`` extra::
+
+    pip install codexlens-search[watcher]
+"""
+from codexlens_search.watcher.events import ChangeType, FileEvent, WatcherConfig
+from codexlens_search.watcher.file_watcher import FileWatcher
+from codexlens_search.watcher.incremental_indexer import IncrementalIndexer
+
+__all__ = [
+    "ChangeType",
+    "FileEvent",
+    "FileWatcher",
+    "IncrementalIndexer",
+    "WatcherConfig",
+]