The Record learns to count pages, not just files

🛰️ Satellite — why pages, and why "known so far"

Files and bytes are a proxy for effort; pages are the real unit of legal reading. The register groups and slices the whole corpus (by type, by tag, by Side, by participant), and every bucket already carries a summary. The missing number is pages. The wrinkle: a document's page count is unknown until it is segmented — fresh uploads sit in a processing state with pageCount === null. We must not block the total on a slow pipeline, nor invent a page count. So the rule is: totals are pages known so far — a still-processing doc contributes 0 to the aggregate, and the row itself shows — until it is segmented.

✈️ Airplane — one aggregate, three surfaces, one toggle

The pure engine (view-state.ts) already folds every group and slice bucket into a Summary. We taught that fold one more field and let every existing surface read it:

• The engine — Summary and SliceOption gain totalPages; the single addToSummary() reducer (and the slice-bucket loop) sum doc.pageCount ?? 0. One place, every bucket.
• The slice navigator — the per-value pill now renders N pages when the field-sum mode is pages.
• The group header — its summary string renders the page total when the mode is pages.
• The View field-sum control — a new Total pages choice sits between Total size and Count + size, and round-trips through the saved view.

🔬 Microscope — the reducer is the whole change

The fold that makes "known so far" true (view-state.ts)

function addToSummary(summary: Summary, doc: RegisterDocument): void {
  summary.count += 1;
  summary.totalSize += doc.sizeBytes ?? 0;
  // Pages are unknown until a doc is segmented; null contributes 0, so the
  // total is "pages known so far" (the row itself shows "—").
  summary.totalPages += doc.pageCount ?? 0;
}

Because every group, every slice value, and the corpus-wide "All" row all flow through this one reducer (and the parallel slice-bucket loop), the new number is correct everywhere at once — no surface re-implements counting.

The field-sum modes gain one member

export type FieldSumMode = "count" | "size" | "pages" | "both" | "none";

// presentation.ts — summaryParts() now returns a third piece:
case "pages":
  return { count: null, size: null, pages: summary.totalPages };

The components localise the page label through next-intl (DocumentsRegister.summary.pages, an ICU plural) — never a hardcoded word — and the control label (DocumentsRegister.fieldSum.pages → "Total pages") ships in both en and hi.

What you can do now

Acceptance

• ✓ Page totals in the slice-navigator per-value summary and the group-header summary.
• ✓ Total pages option in the View field-sum control; round-trips through the saved view.
• ✓ Processing docs show —; totals = pages known so far (null → 0).
• ✓ Wired into the engine where count/size already aggregate — one reducer, every bucket.
• ✓ i18n en + hi for "Total pages" and the page-count plural; semantic tokens only.
• ✓ Storybook: PagesOnly stories on the slice navigator and group header.
• ✓ pnpm lint · test (628) · tsc · build green.

Files changed

13 file(s), +77 / -30 lines