Per-API reference

Grouped-by-domain reference for each implemented API key: versions, semantics, deviations from Apache Kafka 3.7, source paths, test coverage.

All 36 registered keys are documented across seven domain pages — grouped so related behaviour (and shared deviations) read in one place, with a stable anchor per key that the generated matrix links to:

• Produce, Fetch, ListOffsets & Metadata — the data plane
• Consumer-group APIs — find/join/sync/commit and the admin group surface
• Transaction APIs — the EOS surface
• Topic & config admin APIs
• ACL & quota admin APIs
• SASL authentication APIs
• Cluster & log-dir APIs

Every anchor follows the same template:

1. Purpose — what the API does in one or two sentences.
2. Versions — the supported range, matching the registry (the matrix is generated from it, so a mismatch here is a doc bug by definition).
3. Handling — how the request flows through kaas.
4. Deviations — where behaviour differs from Apache Kafka 3.7, stated plainly.
5. Source — handler and codec paths.
6. Verified by — unit/integration tests and scripts/kafka-*.sh scenarios.