Lemenzo Gallery v1.13 — Production Release Candidate

Final release-hardening over v1.12:
- Completed the legacy Android instrumentation runner configuration for Android 16 Soong builds by adding android.test base/mock/runner system stubs and declaring android.test.runner in the test manifest.
- Renamed the user-facing smart category to "Selfies & portraits" to accurately reflect local face detection rather than claiming identity-aware selfie classification.
- Tightened local selfie/portrait detection: requires a single prominent, centered, sufficiently large face and rejects very wide scenes and arbitrary group photos more aggressively.
- Kept all smart analysis local, on-demand, account-free and network-free; no facial identity recognition, embeddings or biometric template database is created.
- Nature/Animals are intentionally not implemented as unreliable heuristics. A future version may add them only with a vetted bundled offline classifier and explicit performance/privacy review.

Release gates:
  tests/run_host_tests.sh
  python3 tests/validate_static.py
  m LemenzoGallery LemenzoGalleryTests
  atest LemenzoGalleryTests
  Pixel runtime/stress matrix in tests/TEST_PLAN.md