feat(health): lead with one score, and let the reader choose what it counts

[RaghavChamadiya]

Based on #2161.

The page led with Code health and Maintainability side by side, both
out of ten and both largely about code shape, so the first screen answered
"which number do I steer by?" twice, with two different numbers. It carries one
figure now. Maintainability moves to the ribbon beside the other cuts of the
same scoring, and Open findings leaves it, since the tab row already counts
them.

One score, and the reader chooses what it counts

A Counts control in the page header answers the question the second figure
was there for. everything is the calibrated score; code_shape removes the
git-derived half — churn, co-change, ownership, prior fixes — which rises as a
file is worked on and so reports what a repository has been through rather than
what its code is like. On this repo that is 7.1 against 8.5, and hotspot health
4.6 against 7.6.

It is a projection, not a second scoring pass. Both halves are already stored
per file and a score is clamp(10 - structure - history), so leaving one out is
a subtraction. The metric rows a route holds are live ORM objects, so the
projection wraps them rather than assigning to them; writing a projected score
onto one would flush it back to the store. A file with no recorded split is
reported as unscored rather than counted as a confident ten.

The reading reaches every surface that could otherwise contradict the headline:
the distribution, the file list and its ranking, the map's colours, the work
queue, the findings list, and the drawer that opens from a row. When change
history is excluded its findings go with it, so what is listed finally sums to
the figure above it.

The trend keeps the full score. Snapshots recorded that, and deriving a series
from mean deductions would disagree with the headline wherever a file sits at
the score floor; its two colliding figures say so rather than printing the
other reading.

Two claims are withdrawn under the projection rather than restated: the band
word, whose thresholds were fitted against the calibrated score and would call
almost any repository healthy here, and the bug-prediction accuracy, which only
the calibrated score earns.

Explaining the figures

Every figure carries an explainer. A number a reader cannot define is a number
they cannot act on, and "Performance risk 942" beside "Hotspot health 4.5"
reads as two scores when one is a count that only goes up. The stat ribbon's
hints were a native title attribute — invisible, unreachable by keyboard and
absent on touch — and are a tooltip now.

Quieter chrome

The band is a dot and a word rather than a filled badge; a description of where
a number sits is not news. In the hotspot table the per-row "Hot" tag labelled
nothing, every churn bar was red because every row of that table is high-churn
by definition, the bus factor wore a tinted pill on ordinary counts, and three
link icons per row competed with the row's own click.

PageShell's actions block wraps instead of refusing to shrink: it sized itself
to its contents and ran off the side of a phone, taking the whole page's
horizontal scroll with it. The two view controls are named dropdowns rather than
four choices spelled out in full.

Verification

• packages/ui 1,671 passed / 193 files; packages/web 84; packages/vscode
  webview 45; root npm run type-check green; ruff check clean.
• Python health and health-route suites green apart from the pre-existing
  grammar families and the generated-contract drift, verified unchanged.
• Both readings checked end to end against a real index across the overview,
  files, findings and map routes, and read out of the rendered page in light and
  dark; horizontal overflow measured at 390px before and after.

[repowise-bot]

🔍 3 things to check

1. PageLede in .../shared/page-lede.tsx signature changed. Review 19 callers outside this PR: .../commits/commit-detail-card.tsx::CommitDetailCard, .../commits/commits-lede.tsx::CommitsLede, .../dead-code/dead-code-lede.tsx::DeadCodeLede (+16 more)
2. ViewTabs in .../shared/view-tabs.tsx signature changed. Review 6 callers outside this PR: .../shared/view-tabs.test.tsx::__module__, .../decisions/decision-review-lanes.tsx::DecisionReviewLanes, .../files/file-page.tsx::FilePage (+3 more)
3. listHealthFindings in .../src/code-health.ts signature changed. Review 3 callers outside this PR: .../core/fileSignals.ts::getFileFindings, .../code-health/coverage-tab.tsx::CoverageTab, .../code-health/performance-tab.tsx::PerformanceTab
   _{...and 5 more, on the PR page}

✅ Health of changed files: 5.8 → 6.2 (+0.4)
_{🚨 Change risk: high, riskier than 82% of this repo's commits.}

✅ Health gate: passed

---

📊 See the full report for this PR
_{Your repo map with this PR's blast radius lit up, every caller of the contracts it changes, and health before and after. No sign-in. · ⭐ Star Repowise · 📥 Install bot · Silence on a single PR with [skip repowise] in the title · Per-repo toggle on repowise.dev/settings?tab=bot · Updated 2026-09-08 16:31 UTC (since the last push: health 6.3 to 6.2)}