Validation: #49 Schema ownership transfer

Validation Result: PASS

What was validated

• pg_dump of production schema captured as db/structure.sql (841 lines, all tables/indexes/triggers/FK constraints)
• config.active_record.schema_format switched from :ruby to :sql
• neighbor gem added for pgvector vector(2560) column on blocks
• First Rails migration: add status VARCHAR(50) to projects — proves migration authority
• 6 rspec tests passing (3 scope tests, 1 default value, 2 column property tests)
• ci_schema.sql updated for CI compatibility (vanilla postgres:17, no pgvector)
• No regressions — 21 pre-existing request spec failures identical on main
• Migration is purely additive — pal-e-docs backward compatibility preserved

Nits (non-blocking)

• by_status scope could benefit from enum validation for self-documentation
• structure.sql intentionally omits new migration version — load pattern worth documenting
• Migration spec typing minor
• No automated CI schema drift detection yet

CI Note