refactor CLI command modules and synchronize docs

CHANGELOG.md

@@ -0,0 +1,38 @@
+# Changelog
+
+## 2026-02-16
+
+### Refactor Results
+
+- Modularized CLI command implementations:
+  - Added `src/vlm/commands/parse.py`
+  - Added `src/vlm/commands/enrich.py`
+  - Added `src/vlm/commands/execute.py`
+  - Refactored `src/vlm/cli.py` to delegate `parse`, `enrich`, `execute`, and `rollback` to command modules
+
+- Unified I/O layer for JSON handling:
+  - Added `load_json_file`, `save_json_file`, `save_analysis_json` in `src/vlm/io.py`
+  - Updated analyze/enrich paths to use unified I/O entry points
+
+- Parser/config consistency improvements:
+  - Added shared `DEFAULT_VIDEO_EXTENSIONS` in `src/vlm/config.py`
+  - Updated `src/vlm/parser.py` to use the shared config constant instead of local hardcoded defaults
+
+- Execution reliability hardening:
+  - Updated `src/vlm/executor.py` transaction logging to fail gracefully when `~/.vlm` is not writable (warn + continue)
+
+- Test stability improvements:
+  - Standardized test timestamps to timezone-aware UTC (`datetime.now(timezone.utc)`)
+  - Added missing `timezone` imports where required
+
+### Verification
+
+- Full test suite passed after refactor:
+  - `477 passed`
+
+### Documentation Sync
+
+- Updated repository documentation set to match the refactor baseline:
+  - Core docs: `README.md`, `AGENTS.md`, `CLAUDE.md`, `GEMINI.md`
+  - Skill docs: `skills/vlm-library-workflow/SKILL.md` and all references under `skills/vlm-library-workflow/references/`
+  - Legacy review/plan docs now explicitly marked as historical snapshots and redirected to `CHANGELOG.md` as the current source of truth