chore: bump version to 0.2.0, write full changelog

- pyproject.toml: version 0.1.0 → 0.2.0
- CHANGELOG.md: full [0.2.0] entry covering all changes since the fork —
  headless operation, Docker/scheduling, object mode, people filtering,
  quality controls, CI/CD, tests, docs, and all bug fixes
- uv.lock: regenerated after version bump

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "winnow"
-version = "0.1.0"
+version = "0.2.0"
 description = "Immich to Frigate training sets"
 license = "MIT"
 requires-python = ">=3.12"