feat(07-unified-service-catalog): add services table to schema with audit trail columns

- New `services` pgTable with: id, name, description, unit_price, category, active, migrated_from, migrated_id, created_at
- Audit trail columns (migrated_from, migrated_id) enable rollback safety during expand-contract migration
- Service and NewService TypeScript types exported
- Migration SQL file created (0001_add_services_table.sql) for schema push
- No FK relations added yet (Phase 8 will establish connections)
- service_catalog, offer_services tables unchanged — legacy compatibility preserved
- npm run build passes TypeScript checks

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/db/migrations/meta/_journal.json

@@ -8,6 +8,13 @@
       "when": 1778705200462,
       "tag": "0000_pretty_typhoid_mary",
       "breakpoints": true
+    },
+    {
+      "idx": 1,
+      "version": "7",
+      "when": 1781151516000,
+      "tag": "0001_add_services_table",
+      "breakpoints": true
     }
   ]
 }