[jonbaldie]

Summary

Closes #166. Queue clients keep the same HEAD behavior. Maintainers can register Peek directly instead of checking the HTTP method inside Dequeue.

HEAD /dequeue/:queue
  Router.head -> Peek -> response headers, no body
GET /dequeue/:queue
  Router.get -> Dequeue -> oldest Payload
Other GET routes
  HEAD falls back to GET when no explicit HEAD route matches

The change covers explicit HEAD priority and body removal. It preserves existing Allow values. Extra HTTP methods and middleware changes are out of scope.

Evidence

• Before: The new router tests report 11 passed | 7 failed because Router.head is absent. Adding registration alone still leaves six dispatch tests failing.
  After: deno test --frozen tests/router_test.ts reports 18 passed | 0 failed. Router and unchanged handler tests together report 162 passed | 0 failed.
• Before: The production binary preserves the Queue on HEAD and returns Allow: GET for an unsupported Dequeue method.
  After: A live HTTP comparison passes all 16 requests on both production binaries with identical results, including FIFO Dequeue and empty-Queue responses.
• deno test --frozen --allow-read --allow-write --allow-net --allow-env --allow-run reports 390 passed | 0 failed, including Docker persistence and the real Stryker runner.
• npm run quality:production passes. CI is green for Test, Production quality, Mutasaurus, and Stryker.

Merge Danger

Door: two-way

A code revert restores the old dispatch. No stored data or configuration changes.

Blast Radius: routing

HEAD dispatch changes inside Router. GET fallback, authentication, Queue preservation, and existing method-error headers have regression coverage.

[jonbaldie]

Verification verdict

PASS+NOTES from the implementing assistant's sequential review fallback. This is not an independent review. The session has no subagent tool.

Reviewed head f46c93d4b2fb38db29c7d3f957d4acd6d0719023 against base 19097c19ed4daa70143ca1e5020052e581d91465. Stable patch-id is 0b6e493f794538be1080b24892ffafbc5c21b711.

• The full Deno suite passes with 390 tests. The production quality gate passes without policy changes.
• Both production binaries compile. A live HTTP comparison passes 16 requests per binary with identical results, including Queue preservation on HEAD, FIFO Dequeue, and unchanged Allow values.
• The new tests fail before implementation and pass afterward. Both registration orders, overlapping patterns, HEAD-only routes, fallback, and response metadata have coverage.
• No comments or suppressions were added. The diff changes only Router, Dequeue registration, and router tests.

Remote CI must finish successfully at this head before merge. Router-generated HEAD error bodies remain unchanged. Normalizing all error bodies is outside this ticket.