fix(#1360): cluster pill shows letter+count — restore count visibility regressed by #1357

[Kpa-clawbot]

Red commit: c0de33a (CI: https://github.com/Kpa-clawbot/CoreScope/actions/runs/26416117686)
Green commit: c268248 — CI: https://github.com/Kpa-clawbot/CoreScope/actions/runs/26416069319

What

Fix #1360 regression: cluster role pills on /map show ONLY the role letter (R/C/M/S/O); the per-role count number that was visible pre-#1357 is gone. This PR restores the count by concatenating it after the letter inside the pill body, so each pill renders as R60, C30, M5, etc.

• public/map.js makeClusterIcon: pill body becomes letter + n (was letter).
• aria-label / title ("60 repeaters") untouched — already correct.
• DOM, classes, CSS, --mc-* constants, border-style ramp, multi-byte labels — untouched.

Adversarial follow-up (commit on top of green)

• JS cap: makeClusterIcon clamps n > 999 → "999+", so pathological clusters render as e.g. R999+ instead of R10000. Pill width stays bounded.
• CSS guard on .mc-pill: max-width: 4ch; overflow: hidden; text-overflow: ellipsis; as defense-in-depth if a render slips past the JS cap.
• +3 test assertions: one for the JS cap, two for the CSS guard. Mutation-verified (removing the cap fails ONLY the new cap assertion).

Why

#1357 fixed WCAG 1.4.1 for cluster role pills by promoting the role letter to the pill body, but in doing so dropped the count number that sighted operators relied on for at-a-glance per-role counts. The letter is the WCAG carrier; the count is the data. Both belong in the pill body — they always did before #1357. The audit's intent was to PAIR them, not REPLACE one with the other.

TDD red→green

• Red (c0de33a9): added test-issue-1360-pill-letter-count.js with assertions that pill body concatenates letter + n and is no longer the bare letter. Fails by assertion against current master. Red CI: https://github.com/Kpa-clawbot/CoreScope/actions/runs/26416117686
• Green (c268248d): one-line change in public/map.js (letter + '</span>' → letter + n + '</span>'). All assertions pass. Green CI: https://github.com/Kpa-clawbot/CoreScope/actions/runs/26416069319
• Follow-up (this push): JS "999+" cap + CSS width guard + 3 new assertions. a11y(map): cluster bubbles + role pills + multi-byte hash labels encode signal by color only (WCAG 1.4.1) #1356 (40), a11y(map+legend): use shape variation per role/type (not color only) + avoid blue-on-blue dot stacking + colorblind-safe palette #1293, and marker-outline-weight tests remain green.
• New test wired into .github/workflows/deploy.yml right after test-issue-1356-map-a11y.js.

Visual verification

Open https://analyzer.00id.net/#/map after deploy and confirm cluster pills display R<count>, C<count>, M<count>, etc. (e.g. R60 C30 M5) instead of bare letters. aria-label="60 repeaters" remains for screen readers. For very large clusters, pills cap at R999+ / C999+ etc.

Fixes #1360

[Kpa-clawbot]

Kent Beck Gate (round 1) — TDD + test quality

Verdict: APPROVED
TDD history: PASS

TDD red→green history (verified)

• Branch commits (oldest→newest):

  • c0de33a9 — test(#1360): RED — assert pill body emits letter + count — touches only .github/workflows/deploy.yml + test-issue-1360-pill-letter-count.js. Tests-only ✓.
  • c268248d — fix(#1360): GREEN — pill body emits letter + count — touches only public/map.js. One-line production change ✓.

• Red CI run 26416117686 → conclusion=failure, log shows:

  • === #1360: pill body emits letter + count (not letter alone) ===
  • ✗ map.js concatenates letter + n (or letter + String(n)) for pill body
  • ✗ pill body is no longer just letter (no '+ letter + "</span>"' pattern)

  Assertion-level failure (not compile/import). Test file ran to completion and failed on its assertions. Red-bar quality bar met ✓.

Six Questions

1. Show me the test that fails when this change is reverted.
Reverting letter + n → letter flips assertions A (/letter\s*\+\s*(?:String\()?\s*n\b/), B (/\+\s*letter\s*\+\s*['"]<\/span>/), and C (template-shape regex). CI run 26416117686 is the proof. ✓

2. Smallest test for the regression.
Assertion A alone (one regex) is the minimal gate. B is a useful negative complement. C duplicates A with looser context. Trio is defensible; not over-elaborate.

3. Could a wrong impl pass?
Stress-tested the harness against plausible wrong concatenations:

• letter + '|' + n, letter + ' ' + n, letter + ', ' + n — A's letter\s*\+\s*(?:String\()?\s*n requires direct adjacency (only String( allowed between); these all fail A. ✓
• n + letter — fails A (no letter + n) AND fails D (/\bn\s*\+\s*letter\b/). ✓
• letter + (n + '...') — fails A (open paren not in alternation). ✓
• \bn\b word boundary prevents accidental match on nbsp, null, etc. ✓
  Harness is appropriately tight for a pure-string test.

4. Edge cases NOT tested.

• 0-count role: verified inert — if (n <= 0) continue; at public/map.js:1515 suppresses zero-count roles before any pill is rendered. Not a regression risk.
• 3-digit count (100+): not tested. Could overflow pill width or wrap badly. Not asserted in DOM/CSS.
• Single-digit n: implicit in regex [RCMSO]\d+$ mentioned in comments, but no assertion actually evaluates the rendered output against that regex (template not invoked).
• Missing ROLE_LETTERS entry: production falls back to '?' → pill body becomes ?5. Not asserted; behavior preserved but undocumented.
• All of these are out-of-scope for a 1-line regression fix — flagging as nits, not must-fix.

5. Test names describe behavior or implementation?
Mixed but defensible. "concatenates letter + n for pill body" leans implementation-y, but since the pure-string approach IS the test methodology, the name accurately describes what's being asserted. "pill body is no longer just letter" and "letter precedes count in concatenation" are behavior-oriented. Acceptable.

6. Pure-string approach defensible?
Yes. public/map.js is a Leaflet-bound browser IIFE that cannot be require()'d in Node. Pattern mirrors the already-accepted test-issue-1356-map-a11y.js and test-issue-1357-* precedents. DOM is built via string concatenation, so source-grep ≈ output-grep. Same answer as the #1357 polish: defensible, with the well-known caveat that a runtime rename of letter/n would defeat the harness. Not blocking.

Must-fix

0.

Out-of-scope nits (for future hardening, not this PR)

• Add a 3-digit count assertion (e.g., construct a synthetic call to confirm pill body matches /^[RCMSO]\d{1,3}$/).
• Consider one tiny "execute the template" test via Function-eval'd extraction of makeClusterIcon, but that's a larger refactor than this PR warrants.

Gate verdict: PASS — ship it.

[Kpa-clawbot]

Independent review (round 1)

Verdict: NEEDS-WORK (2 must-fix)

Tiny, well-scoped diff. The 1-line change in makeClusterIcon correctly concatenates letter + n before </span>; ARIA / title / class / style strings are unchanged; if (n <= 0) continue; already suppresses zero-count pills (so the new shape R60 / C30 won't ever render as bare R0). Workflow wiring is correct (slots in right after the #1356 test). Confirmed test-issue-1356-map-a11y.js and test-issue-1293-marker-shapes.js are byte-unchanged on the branch (no quiet edits). Red commit c0de33a9 failed on assertion in CI (proper TDD red, not a build error); green commit c268248d passes.

Must-fix

1. PR body: Red commit URL missing. Body says c0de33a9... (CI: pending — see checks). AGENTS.md requires Red commit URL in PR body. Add https://github.com/Kpa-clawbot/CoreScope/actions/runs/26416117686 (or the failed Go Build & Test job link) and note the failed assertion line.
2. Acceptance criterion WS handlers trigger full page reloads on every packet — no debouncing #7 not addressed (4+ digit graceful handling). Issue explicitly calls for it; public/style.css:3346 .mc-pill has only min-width: 12px; padding: 0 3px with no overflow, no max-width, no text-overflow, and .mc-pills has no flex-wrap / overflow: hidden. Cluster wrap is 48px (56px mc-lg); 4 pills of R1000-shape (~5 chars × ~5px + 6px padding ≈ 31px each → ~124px) will overflow the cluster bubble. Either (a) add overflow: hidden; text-overflow: clip + max-width on .mc-pill and overflow: hidden on .mc-pills, or (b) cap rendered count (e.g. n > 999 ? '999+' : n) in map.js, or (c) explicitly state in PR body that WS handlers trigger full page reloads on every packet — no debouncing #7 is deferred and open a follow-up issue.

Out-of-scope (not blockers)

• Test assertion E (ROLE_LETTERS map contents) is mostly tautological — asserts the map is defined but not that the pill body actually emits one of those letters. Assertions B and D are the ones doing real work; the test as a whole is gating (Red commit proved it). Acceptable per the "mirrors a11y(map): cluster bubbles + role pills + multi-byte hash labels encode signal by color only (WCAG 1.4.1) #1356 pattern" note, but a future hardening could shell out to a DOM-grep style check that the rendered HTML matches /^[RCMSO]\d+$/.
• The pillTemplateRe (assertion C) is essentially a duplicate of assertion A with a 400-char window — non-harmful, but trim-worthy.

Confirmed clean

• ARIA: aria-label="' + n + ' ' + role + ... and title="..." unchanged → screen readers still announce "60 repeaters", not "R60 repeaters". ✓
• ROLE_LETTERS sourced (no hardcoded letters in DOM build). ✓
• Fixes #1360 present. ✓
• No edits to a11y(map): cluster bubbles + role pills + multi-byte hash labels encode signal by color only (WCAG 1.4.1) #1356 / a11y(map+legend): use shape variation per role/type (not color only) + avoid blue-on-blue dot stacking + colorblind-safe palette #1293 tests. ✓
• CI green on head (c268248d): Go Build & Test pass 7m5s, Playwright pass 6m23s, Docker pass. ✓