Closes the Fase-15 cycle. Final counts: 177 pgTAP + 179 Vitest
integration + 47 Vitest unit + 93 Playwright + 1 gated = 497 + 3
skipped. The plan estimated +14; actual is +21 (the extra came from the
schema-invariant pgTAP assertions on the new index + RPC posture).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
