Use this section for implementation internals and maintenance workflows.
docs/development/ARCHITECTURE.mddocs/development/CONFIG_FIELDS.mddocs/development/CONFIG_FLOW.mddocs/development/TESTING.mddocs/development/UPSTREAM_SYNC.md
docs/development/ARCHITECTURE.md- runtime architecture, module boundaries, and request flow.docs/development/CONFIG_FIELDS.md- canonical config schema and option semantics.docs/development/CONFIG_FLOW.md- config load/merge resolution behavior.docs/development/TESTING.md- test strategy and verification commands.docs/development/UPSTREAM_SYNC.md- how we track/sync upstream behavior.docs/development/ULTRA.md- default-off GPT-5.6 Ultra WIP contract and rollout guidance.docs/development/PROMPT_COMPATIBILITY.md- pinned-source build workflow for adapting Codex prompt overlays to the OpenCode harness.docs/development/OPENCODE_V1_17_18_SYNC.md- detailed v1.3.0 to v1.17.18 parity audit and disposition.docs/development/upstream-watch.json- upstream watch state artifact.