Use PostgreSQL as the only database backend across runtime, schema tooling, installation, Compose, and CI. Update regression tests and reject removed drivers explicitly.
Consolidate subscription usage policy enforcement, privacy-safe persistence, and gateway security hardening into one reviewable change.
Includes bounded HTTP and execution envelopes, header and protocol guards, DNS and relay validation, authentication and secret projection hardening, secure backup/install paths, and regression coverage.
Align MySQL and SQLite schemas, migrations, usage, stats, export, and backfill behavior with the shared data contracts. Extend gateway startup and maintenance support across all SQL drivers.
Shard and singleflight hot-path caches, batch and prioritize candidate and usage lifecycle persistence, and extend database and pressure-test instrumentation for 20k concurrent streams.