weichen
f705f99b8f
Why: collaboration storage U7 (proposal sections 3/5/7) requires two-process HTTP-level acceptance over shared PG, a reproducible load-test entry honoring the load contract, and an auditable pre-release checklist; capacity windows and dual-host runs need user-scheduled resources, so the deliverable here is the verifiable entry, not capacity claims. Evidence: make test green (composite); make test-multi-instance green locally against an isolated PG (five scenarios incl. crash-takeover and restart invariants); run_load.sh --profile smoke end-to-end green (SSE probe p95~18ms, zero seq duplicates, stack auto-recycled); backend pinned to feature branch with the three cross-instance fixes. Impact: new tests/integration/multi-instance (CI test-pg job step), new tests/load/collaboration (k6 + SSE probe + run_load.sh), release checklist at docs/release-multi-instance.md; no runtime behavior change in Dev repo itself. Refs: backend PR #164; task card feature/u7-load-fault-release.
ui
@ bfecf8b51f