feat(review): auto-trigger E2E test generation on manifest_missing_tests

[JSONbored]

Summary

• Promotes the existing manifest_missing_tests advisory finding (already computed whenever a repo opts into review.test_expectations + manifestPolicyGateMode) into an actual auto-trigger for the feat(review): resolver gate for e2eTests — src/review/e2e-test-gen.ts #4192/feat(review): dispatch wiring for e2eTests in queue/processors.ts #4194 generation-and-render path — additive to the explicit @gittensory generate-tests command (feat(commands): wire @gittensory generate-tests PR-comment command #4195), which stays available regardless of whether this signal fired.
• Extracts the generation-and-delivery core shared by both triggers into runE2eTestGenerationAndDeliver, so the explicit command and the auto-trigger can never silently drift apart.
• Adds a per-head-SHA double-generation guard (hasAuditEventForHeadSha, mirroring hasAuditEventForDelivery's own json_extract pattern) so a re-review/sweep pass over an unchanged commit never re-spends an LLM call or reposts a duplicate suggestion — a genuinely new push (a new head SHA) is always a fresh miss regardless of how many prior SHAs already fired.
• The explicit command deliberately does not consult this guard: a maintainer typing the command always gets a fresh generation, even on a SHA the auto-trigger already covered (simplicity over a cache that would need its own invalidation rules — documented as the deliberate resolution to issue feat(review): auto-trigger E2E test generation on the manifest_missing_tests signal #4196's own flagged open question).

Closes #4196

Scope

• The PR title follows type(scope): short summary Conventional Commit format.
• This PR is focused and does not mix unrelated backend, UI, MCP, docs, dependency, and deploy changes.
• This follows CONTRIBUTING.md and does not reintroduce GitHub Pages, VitePress, site/, or CNAME.
• I linked a currently open issue this PR resolves.

Validation

• git diff --check
• npm run actionlint
• npm run typecheck
• npm run test:coverage locally (unsharded) — 100% branch coverage on every changed/new line in this diff, confirmed via raw lcov BRDA data, not just the summary table.
• npm run test:workers
• npm run build:mcp
• npm run test:mcp-pack
• npm run ui:openapi:check
• npm run ui:lint
• npm run ui:typecheck
• npm run ui:build
• npm audit --audit-level=moderate
• New or changed behavior has unit/integration tests for new branches, fallback paths, and sanitizer boundaries — including: signal-fires+feature-enabled auto-trigger, feature-disabled no-op, test-file-present no-op, validation-note-present no-op, double-generation dedup on an unchanged head SHA, fresh generation on a genuinely new head SHA, the explicit command still regenerating on a SHA the auto-trigger already covered, agentPaused/agentDryRun skip, and the author-less (author ?? "the PR author") attribution fallback.

Also ran (this repo's test:ci covers more than the template lists): npm run db:migrations:check, npm run db:schema-drift:check, npm run selfhost:env-reference:check, npm run selfhost:validate-observability, npm run cf-typegen:check, npm run test:engine-parity, the @jsonbored/gittensory-engine package's own tests, npm run build:miner, npm run test:miner-pack, npm run rees:test, npm run ui:openapi:settings-parity, npm run ui:version-audit, npm run docs:drift-check, npm run manifest:drift-check, npm run command-reference:check, npm run ui:test.

Safety

• No secrets, wallet details, hotkeys, coldkeys, user PATs, private keys, raw trust scores, private rankings, or private maintainer evidence are exposed.
• Public GitHub text stays sanitized, low-noise, and does not imply compensation guarantees or optimization tactics.
• Auth, cookie, CORS, GitHub App, Cloudflare, or session changes include negative-path tests (agentPaused/agentDryRun both covered).
• API/OpenAPI/MCP behavior is updated and tested where needed (no OpenAPI/MCP surface changed by this PR).
• UI changes use live API data or real empty/error/loading states, not production mock/demo fallbacks (no UI changed).
• UI Evidence — not applicable, no visible UI/frontend/docs/extension change in this PR.
• Public docs/changelogs are updated where needed (none needed for this piece); changelog itself is untouched.

Notes

• This is the last engineering issue in the Epic: AI-generated E2E test coverage for pull requests #4189 AI-generated E2E test coverage epic. chore(review): enable + validate E2E test generation end-to-end #4199 (enable + validate end-to-end against real traffic) remains — it is a production-enablement/observation task, not an engineering one, so it needs the maintainer's own go-ahead to flip the live flag rather than being completed autonomously.

[superagent-security]

Superagent didn't find any vulnerabilities or security issues in this PR.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (main@f498e70). Learn more about missing BASE report.
⚠️ Report is 2 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4316   +/-   ##
=======================================
  Coverage        ?   93.81%           
=======================================
  Files           ?      398           
  Lines           ?    36780           
  Branches        ?    13443           
=======================================
  Hits            ?    34506           
  Misses          ?     1620           
  Partials        ?      654           

Files with missing lines	Coverage Δ
src/db/repositories.ts	96.71% <100.00%> (ø)
src/queue/processors.ts	95.45% <100.00%> (ø)

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