CHANGELOG 1.3.10 (unreleased) with behaviour-change and breaking
sections, README capability rows and a 1.3.10 section, ARCHITECTURE
section 15 plus 6.2/7 updates, schema doc for the stream_end column,
migration impact notes, ROADMAP entry, .env.example MISSING_DONE
semantics, and a revision pointer on the 1.3.9 design. Follow-ups
filed as #32 and #33.
Add faithful single-choice chat results, tool stream activity, error-frame retries, and isolated protocol caching.
Reject empty cached completions with the same value predicate as transport, add regression coverage, and adopt Apache-2.0.
iomgaa