META: complete-ORM roadmap — retire JsonQueryBuilder & raw SQL for consumers

[teetangh]

Goal (per Kaustav): the generated typed client covers every query the familiarise backends need — JsonQueryBuilder and hand-written SQL become internal implementation details, never consumer-facing.

Shipped in v0.6.0 (unreleased)

• @map / @@map parsing + field→column translation in WHERE/INSERT/UPDATE/ORDER BY
• @updatedAt auto-fill on create, refresh on update
• BigInt @default model generation
• Composite @@id delegate guard
• enum[] / custom array decoding (binary + text wire formats)
• One-to-one FK-on-target relation resolution (nested include fix)

Remaining (ordered by impact on the consuming app)

• Interactive transactions: $transaction with transaction-scoped delegates #68 Interactive transactions ($transaction with scoped delegates) — unlocks booking algorithm
• Support nested writes (create/connect within create/update) #64 Nested writes (create/connect/disconnect)
• Typed include/select with relation hydration on generated models #67 Typed include/select + relation hydration on models
• upsert(): create-or-update by unique key (INSERT … ON CONFLICT) #66 upsert()
• First-class groupBy and aggregate on delegates #65 First-class groupBy/aggregate — unlocks dashboard stats
• Query parity: cursor pagination, Json path filters, scalar-list filters #69 Cursor pagination, Json filters, scalar-list filters
• Connection pooling for server workloads (postgres Pool) #70 Connection pooling for servers

Out of scope for now

Views / composite types / multi-file schemas, MySQL & MongoDB adapters, middleware/$extends.

Consumer-side tracking: Practitionist/familiarise_mobile#106 (223 remaining JQB call sites migrate as these land).