docs: consolidate CLAUDE.md (merge audit sections, dedupe, fix stale facts); runbooks to docs/release.md

Applied the two-review consolidation: merged the duplicate 2026-06-06/06-09 'Conventions (enforced)' sections into one canonical block (query-invalidation rule stated once instead of three times, Zod-helper 'tracked follow-up' vs 'MANDATORY' contradiction resolved, seed-is-dev-only stated once); removed stale-by-design facts (version pins, test counts, file counts, React 18 typo) and migration-era storytelling; fixed prisma migrate diff flags (--from-url removed in Prisma 7) and documented the non-interactive migration recipe; added the new rules earned this week (@db.Date UTC-truncation, document business rules incl. VAT-only-on-invoices and PO suppliers, document-platform conventions, shared-module reuse list, dashboard invalidation, app_test migrate step). Release/hotfix/drift/baseline runbooks moved to docs/release.md with a pointer (keeps prod details out of every-turn context). Also dropped the db:push npm script - it contradicted the golden rule. CLAUDE.md: 570 -> ~390 lines.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

package.json

@@ -14,7 +14,6 @@
     "preview": "vite preview",
     "db:generate": "prisma generate",
     "db:pull": "prisma db pull",
-    "db:push": "prisma db push",
     "db:studio": "prisma studio",
     "test": "vitest run",
     "test:watch": "vitest",