QA Summary: fix-4420

Scope

• PR #4421 is pure and scoped to two files:
  • packages/omo-opencode/src/hooks/team-session-events/team-member-error-handler.ts
  • packages/omo-opencode/src/hooks/team-session-events/team-member-error-handler.test.ts
• Contributor PR already targeted the stale session-error guard. Follow-up work completed guard coverage by moving the decision into the locked runtime-state transition and gating side effects on the same decision.

RED -> GREEN

• RED: red-guard-reverted-team-session-events.txt
  • Command: PATH="$HOME/.bun/bin:$PATH" bun test packages/omo-opencode/src/hooks/team-session-events
  • Setup: guard temporarily reverted to the old name-only errored transition.
  • Observed: the new regression failed because worker session replacement-session was clobbered to status errored.
• GREEN: green-team-session-events.txt
  • Command: same focused suite with the guard restored.
  • Observed: 40 pass, including #given fallback retry replaces a member sessionId #when stale session.error settles #then replacement stays running without a member_error announcement.

Type And Static Checks

• typecheck-after-install.txt: bun run typecheck passed after refreshing dependencies post-merge.
• typecheck-omo-opencode.txt: targeted tsgo --noEmit -p packages/omo-opencode/tsconfig.json passed.
• no-excuse-typescript.txt: TypeScript no-excuse scan passed for both changed files.
• loc-check.txt: handler is 222 pure LOC; existing test file is 387 pure LOC. The test file-size smell is carried because the required fork takeover is a mechanical two-file bug fix and splitting the existing suite would be unrelated architecture churn.

OpenCode QA

• opencode-qa-common-self-check.txt: opencode-qa harness dependencies and isolated XDG sandbox behavior passed.
• opencode-qa-sse-self-test.txt: isolated OpenCode SSE /event surface opened and delivered server.connected.
• session-error-sse-proof.txt: isolated OpenCode server loaded the local plugin, drove prompt_async against a local provider returning a non-retryable context error, observed session.error on /event, and proved the real OpenCode DB session count stayed unchanged (21744 before and after).
• session-error-event.json: captured first matching session.error event with ContextOverflowError from the local failing provider.
• Live two-member provider-quota race reproduction was intentionally omitted: it would require real provider quota exhaustion and timing a concurrent fallback retry. The deterministic test is the faithful channel because it controls the exact session.error interleaving: the fake OpenCode status call swaps the member to a replacement running session before the error handler resumes, then asserts state, pending-delivery reservation, and lead inbox side effects.

Cleanup

• opencode-qa scripts self-cleaned their isolated sandbox.
• Test temp directories are registered in afterEach and removed with rm(..., { recursive: true, force: true }).