Wave 1 Review Summary

All 4 Wave 1 reviewers have returned verdicts. Wave 1 gate: PASS ✅

architecture

Clean fix. Correct layer and scope — MountPoint internal utility. Type-based is_a?(Class) guard is sound and stable. Guard ordering appropriate. New test uses real engine class. No new dependencies or coupling. No changes needed.

security

No security implications. Pure control-flow guard on internal Rack middleware unwrapping utility. No new input handling, deserialization, or network calls. Existing depth guard retained.

simplicity

Single guard clause addition — minimal surface area. Inline comment explains the non-obvious Class check clearly. Test is direct and minimal. Follows existing guard-then-recurse pattern exactly.

rails-conventions (PASS_WITH_NOTES)

Two LOW-severity documentation style nits — neither blocks merge:

1. New YARD doc drops +…+ inline-code delimiters used elsewhere in the file.
2. Inline comment is slightly verbose for a one-liner guard — could be consolidated into the YARD doc.

Proceeding to Wave 2 (rails-security, database, test-quality).

Wave 2 Review Results — All Passed ✅

rails-security: PASS — Zero security surface; internal routing utility guard clause only. No user input, no auth, no views.

database: PASS — No database-related changes in this PR. Pure Ruby routing utility only.

test-quality: PASS_WITH_NOTES (LOW) — New regression test test_unwrap_app_stops_at_class directly covers the fix, well-named and deterministic. Two optional coverage notes (nested-depth test, explicit middleware chain test) — non-blocking.

All Wave 2 reviewers passed. Proceeding to Wave 3 (performance, frontend, accessibility).

Wave 3 Review Results — All PASS ✅

performance (PASS): Trivially cheap is_a?(Class) guard terminates recursion earlier in Engine cases. Net positive — no allocation, no IO, no hot-path impact.

accessibility (PASS): No accessibility surface area — pure backend Ruby routing utility change. No UI, views, HTML, CSS, or JS touched.

frontend (PASS): No frontend code in this diff — pure Ruby files only. Rack app-traversal utility with no client-side surface area.

Wave 3 complete. Proceeding to Wave 4 (documentation).

✅ All Review Waves Passed

All reviewers returned PASS or PASS_WITH_NOTES. This PR is merge-ready.

• Wave 1 (Foundation — architecture, simplicity, security, rails-conventions): ✅ All PASS
• Wave 2 (Correctness — rails-security, database, test-quality): ✅ All PASS
• Wave 3 (Quality — performance, accessibility, frontend): ✅ All PASS
• Wave 4 (Documentation): ✅ PASS — minor docstring precision nit (non-blocking)

Documentation reviewer note: Docstring could be marginally more precise — unwrap_app may return a Class that responds to :app; "innermost non-wrapper app" is slightly ambiguous but acceptable.

Labeled merge:ready + merge:hold. Hold window: 60 minutes from ~15:39 ET. Auto-merge eligible after ~16:39 ET.