Phase 6 — Verify (Iteration 1)

Adversarial pass. Per the cycle, the full suite was re-run from scratch rather than trusting Execute's self-report, and combined with the user's direct hands-on verification of the rendered artifact in a real browser.

Test suite — fresh re-run (not copied from Execute)

Suite	Scope	Result
`tests/test.js` (standalone engine)	optimality, no-path, path validity, edge cases	44/44 pass
`tests/verify_inlined.js` (shipped engine)	re-extracts engine from the HTML and re-asserts	42/42 pass
`tests/verify_inlined.js` (static)	innerHTML/eval/Function/fetch/XHR/storage/external-URL scan	8/8 clean
`tests/integration.js` (jsdom)	build, paint, endpoints, full Play race, Step, reset, no-path	20/20 pass

Headless race (reproduced this run): cost [44, 36, 44, 36], visited [319, 417, 21, 261], optimal [✗, ✓, ✗, ✓] — the intended teaching contrast holds.

Acceptance criteria — evidence

#	Criterion	Verdict	Evidence
1	Offline, no network, no console errors	PASS	Static: 0 external URLs / 0 storage / 0 fetch. No errors in jsdom. User: no console issues, runs offline.
2	Four panels, same maze, shared legend	PASS	integration (4 panels, paint propagates); user visual
3	Paint walls/weights/erase + drag endpoints, reflect in all four	PASS	paint propagation auto-tested; endpoint drag confirmed by user hands-on
4	Random + Clear never strand start/end	PASS	`reachable()` retry + guards; user exercised Random/Clear directly
5	Play lockstep · Step one each · Reset clears	PASS	integration (Step→visited==1 each; reset clears overlays); user
6	Speed slider changes pace	PASS	user confirmed slider feel/pace
7	Dijkstra & A* equal optimal cost; A* visits ≤ Dijkstra	PASS	36==36; 261 ≤ 417
8	BFS/Greedy can be costlier than optimal	PASS	44 > 36
9	Scoreboard live visited/cost/steps/optimal	PASS	integration; user
10	Final path drawn per panel	PASS	integration (`.cell.path` > 0 in every panel); user
11	Seal goal → "No path", no crash	PASS	integration (all four report "no path", cost ∞)
12	No innerHTML/eval/fetch/external URLs	PASS	8/8 static checks

12 / 12 acceptance criteria pass.

Security check results

Offline single-file artifact: no network, storage, auth, or secrets — no attack surface.
Static scan clean: no innerHTML, eval, new Function, fetch, XMLHttpRequest, localStorage/sessionStorage, or external/protocol-relative URLs.
DOM is built exclusively via createElement + textContent; no injection path.

User (human) verification — recorded

User confirmed directly in a real browser: demo works well, looks great, all buttons and features functional. This closes the visual/interaction items automation could not judge (rendering fidelity, layout, slider feel, endpoint dragging, random/clear by hand).

Issues found

None. No regressions, no failing criteria, no security findings.

Outcome

Iteration 1 complete. All acceptance criteria pass with evidence; no issues carried forward. The stepable-engine architecture and shared-maze/four-view design are validated and provide a clean foundation for iteration 2 (teaching content + toggleable pseudocode execution).