fix: direct venv python in entrypoint, fix INSIGHTFACE_HOME path, add badges

- entrypoint.sh: replace `uv run` with `/app/.venv/bin/python` to skip
  uv's sync check which was re-downloading ruff and rebuilding the package
  on every container startup
- compose.yml, .env.example: fix INSIGHTFACE_HOME /models → /models/.insightface;
  InsightFace appends models/ to root, so /models produced /models/models/buffalo_l
- README.md: add Immich and Frigate badges from upstream
- CHANGELOG.md, pyproject.toml, uv.lock: bump to 0.2.1

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

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "winnow"
-version = "0.2.0"
+version = "0.2.1"
 description = "Immich to Frigate training sets"
 license = "MIT"
 requires-python = ">=3.12"