feat: count data visuals separately from decorative elements

[jonathan-pap]

Summary

Visual counts now reflect what users mean by "visuals" — only data-bound canvas elements (charts, tables, cards, slicers, maps, AI visuals, custom visuals). Decorative shapes, textboxes, images, action buttons, page navigators, and visual groups no longer inflate the totals.

What changed

• report-scanner: new isDataVisual predicate (denylist of non-data visualType strings) and a per-visual flag on ScannedVisual. Track dataVisualCount per PageMeta and across the whole scan.
• data-builder: surface PageData.dataVisualCount, allPages entries, and FullData.totals.dataVisuals.
• md-generator + client: switch the user-facing counters — header KPI, per-page stats, page-index bullets, hidden-page table, Pages table in the data-quality MD — to the data-only count.
• Kept the raw visualCount as the source for the wireframe (needs every shape to render the layout) and the empty-state check that distinguishes "blank page" from "decorative only".
• No change to the Sources tab / Sources.md — PhysicalSourceEntry.visualCount was already binding-derived (counts only visuals consuming model fields), so it was already correct.

Why a denylist not a binding check

Considered "count if has bindings" but went with a visualType denylist:

• Future-proof — an unknown custom visual still counts as data (binding check would have to be perfect to match)
• Matches user mental model: "I dropped 5 chart placeholders" = 5 visuals, even if fields aren't bound yet
• Denylist is small and stable: shape, basicShape, textbox, image, actionButton, pageNavigator, bookmarkNavigator, group

Tests

• New tests/report-scanner.test.ts with a minimal PBIR fixture under tests/fixtures/scanner-pbir/: 1 chart + 1 shape + 1 textbox + 1 image + 1 button + 1 unknown custom visual. Asserts visualCount=6, dataVisualCount=2 (chart + custom), and each ScannedVisual carries the right isDataVisual flag. Plus defensive cases on the predicate (case/whitespace/missing).
• Updated factory totals in 6 existing test files for the new dataVisuals field.
• Updated md-tier1.test.ts page-section assertion to read dataVisualCount.
• Updated render-xss-fuzz.test.ts PageData / allPages fixtures.

375/375 tests green. Browser bundle rebuilt (docs/index.html + baked docs/sample-data.json).

Test plan

• CI green on Node 18 / 20 / 22.
• Open docs/index.html locally — confirm the header Visuals KPI drops vs. the previous main (sample has decorative elements on at least one page).
• Hover the Visuals KPI — tooltip now explains the new semantics.
• Page card "Visuals" stat reflects data-bound only; "Visuals (N)" section heading matches the list rows.
• Pages MD doc on a real model — totals + per-page bullets show the data-only number.