The partitioned event schema changes the primary key shape for append-only event and activity tables.

Add schema assertions for the created_at-aware keys and mirror that shape in the SQLite service test fixture.

Tests now catch regressions that would make the monthly partition DDL incompatible with the Go models.

The database optimization plan should reflect the completed monthly partitioning slice for event and activity tables.

Mark the Phase 4 checklist item complete and add the new schema and test files as verification entry points.

The roadmap now shows the remaining Phase 4 work around browser sessions, collaboration batches, cold export, and recovery.

Review found that monthly partitions could age out in long-lived processes and extension event deduplication was no longer a durable database invariant.

Add default partitions for event tables and introduce an unpartitioned extension event claim table keyed by event id.

Future-dated event inserts now have a partition fallback, and duplicate extension callbacks are blocked consistently across database backends.

Duplicate extension callbacks need idempotent claim handling on PostgreSQL without aborting the transaction.

Schema sync now backfills extension event claims and drains default rows into real monthly partitions.

Existing callbacks stay deduplicated and future partition maintenance preserves pruning.

Archived extension events leave durable callback claims behind after the event rows are removed.

The archive delete phase now runs an optional hook and removes claims for archived extension event IDs in the same transaction.

Old claims stop blocking reused event IDs while hot event claims remain intact.