chore(memory): update code-reviewer agent notes on scoring and quality gates

Capture scoring ladder implementation details, regional scoring board crediting
mechanics, and quality gate findings from UI/UX quick wins review cycle.

.claude/agent-memory/code-reviewer/MEMORY.md

@@ -1,2 +1,3 @@
 - [Anti-cheat invariant and its known bypass](project-anti-cheat-invariant.md) — pano coords are the answers; the import-walk test does not cover the debug API that leaks them.
-- [Quality gate blind spots](project-quality-gates-blind-spots.md) — no-undef is now on, but no gate checks React prop/state contracts or whether /docs matches the code.
+- [Quality gate blind spots](project-quality-gates-blind-spots.md) — no-undef is now on, but no gate checks React prop/state contracts, e2e stub drift, or whether /docs matches the code.
+- [Scoring ladder vs leaderboard boards](project-scoring-ladder-and-boards.md) — no single ladder any more: each board is credited by its own, and the headline score is credited to none.

.claude/agent-memory/code-reviewer/project-quality-gates-blind-spots.md

@@ -14,8 +14,21 @@ tests and no `@testing-library` dependency - every suite is lib/API level.
 **Closed since 2026-08-30:** `eslint.config.mjs` now adds `no-undef: error` and
 `no-unused-vars: warn` on top of `next/core-web-vitals`, with browser+node
 globals. That kills the original failure (six `useState` declarations deleted,
-ten setter call sites surviving green). Lint currently emits 4 pre-existing
-`no-unused-vars` warnings; treat any new one as a signal.
+ten setter call sites surviving green). Verified 2026-08-31: lint is 0 errors /
+16 warnings, all `react-hooks/set-state-in-effect` or `react-hooks/refs` and all
+matching an established local pattern (localStorage read in an effect, callbacks
+mirrored into refs). Re-count with `npx eslint . -f json` rather than trusting a
+remembered number; treat a warning of a NEW rule id as the signal.
+
+**Partly closed 2026-08-31:** a Playwright lane exists (`npm run test:e2e`), but
+every API is stubbed in `tests/e2e/helpers.js`, whose own header says the stubs
+mirror the real route shapes and must be updated with any contract change. That
+is a manual promise no gate enforces: the `gameResult.bands` field was added to
+`/api/guess` and the stub was not updated, so the UI block gated on it rendered
+in zero tests. The stub also serves the SAME panorama URL every round, so
+`PanoramaViewer`'s `key={imageData.url}` never changes and "next round loaded"
+assertions pass without a viewer remount. On any diff touching an API response
+shape or the round transition, open `helpers.js` and check it moved too.
 
 **Still open, verified 2026-08-30 on the Phase 6 docs review:**
 - React prop/state contracts. `no-undef` does not see a prop a parent forgot to

.claude/agent-memory/code-reviewer/project-scoring-ladder-and-boards.md

@@ -0,0 +1,33 @@
+---
+name: project-scoring-ladder-and-boards
+description: Scoring is region-relative and each board is credited by its OWN ladder as of 2026-08-31 - what that did to the country board, and what the headline score now means
+metadata:
+  type: project
+---
+
+As of 2026-08-31 there is no single scoring ladder. `calculateScore(distance,
+bands)` takes one, `bandsForBbox(bbox)` builds it from a region's bbox diagonal
+(reference 10 km, factor clamped at >= 1), and there are two different consumers:
+
+- `/api/guess` grades the HEADLINE `gameResult.score` against the region the
+  player PICKED. This number is credited to no board — it is display only.
+- `submitRoundScore` credits each board from the raw distance against THAT
+  board's own ladder, so a country round can no longer buy district points.
+  Each level's award comes back as `levels[].points`.
+
+**Why:** without scaling, a country round was a guaranteed string of zeros. The
+first fix (picked-region ladder + flat fan-out) let a country round credit
+district boards at country precision; the per-level fan-out closed it.
+
+**How to apply:** measured ladders — country 5 pts <= 6,380 m, TPHCM 442 m,
+TPHCM-Q7 62 m, HN-BADINH 50 m. `SCORE_BANDS` is NOT "the district ladder", and
+calling it that in UI copy or docs is wrong: only 20 of 58 playable districts sit
+at factor 1.00; median is 1.51 (TPHCM-BINHTAN, 15.1 km) and max 4.73
+(TPHCM-CANGIO, 47.3 km). It is the ladder for any region up to a 10 km diagonal.
+Consequence the user has not explicitly signed
+off: the Vietnam board now pays +5 for any guess within 6.4 km, so it measures
+rounds played rather than accuracy, and mixes with points banked under the old
+50 m ladder. Anything that bands, colours, or labels a score must say which
+ladder it means; the boards store no record of which one applied. Related:
+[[project-anti-cheat-invariant]] (`bands` leaks nothing — the picked region is
+already client-side).