test: update tests for lexicon migration and selfLabels structure
Updates all tests to use new social.coves.community.post namespace and
structured com.atproto.label.defs#selfLabels format.
Changes:
- Update test data to match new lexicon schema (author field, facets, etc)
- Update integration tests to use SelfLabels{Values: []SelfLabel{...}}
- Update vote_repo_test to use new namespace
- Update post creation tests for label validation
- Update E2E tests for community post namespace
All lexicon validation tests passing (64 pass, 2 skip for defs files).
All integration tests passing with JSONB label storage.