Werk de frontend-documentatie bij

De README noemde App.tsx nog de orchestrator; die rol ligt sinds de splitsing
bij WorkbenchApp.tsx. Verder twee secties toegevoegd over wat er veranderd is:
de werkstanden en het leidende designsysteem, en de laadstrategie met de
verzoekdeler en het laden per werkblad.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

frontend/README.md

@@ -160,7 +160,9 @@ font dependency.
 
 ## Current component boundaries
 
-`App.tsx` remains the shared workspace orchestrator, while focused surfaces
+`App.tsx` only decides which of the two shells to show: the landing page or the
+workbench. `WorkbenchApp.tsx` is the shared workspace orchestrator and is loaded
+lazily, so the sign-in screen does not pay for the map engine. Focused surfaces
 and pure map helpers are kept outside it:
 
 - `components/overview/OverviewWorkspace.tsx` owns status, source freshness,
@@ -836,3 +838,45 @@ The audit covers 390x844, 1366x768 and 2560x1080, every top-level workspace,
 keyboard operation of the analysis period, skip-link focus, delayed bootstrap
 truthfulness and visible coverage timing. The enforced limits are documented
 in `docs/UX_PERFORMANCE_BUDGETS.md`.
+
+## Visual audit follow-through
+
+The workbench runs dark by default; the landing page stays light. A toggle in
+the top bar switches between them and remembers the choice per browser. The
+operating system preference is deliberately ignored: browsers report `light` by
+default even when the user never chose, which would put almost everyone in the
+wrong mode.
+
+`styles/geointel-system.css` is loaded last and leads. Thirteen tokens were
+called on 87 lines without ever being defined, so those colour declarations fell
+back to inheritance; they now resolve. Shape and elevation went back onto the
+scale, and the weight scale has four steps that are each actually loaded — the
+stylesheets previously declared nine weights while two faces were available, and
+`font-synthesis-weight: none` meant everything from 650 to 850 rendered as 600.
+
+Real `!important` went from 47 to 1, verified by comparing computed styles
+between production builds. The remaining one is documented where it stands.
+Fifteen of the removed ones sat in the second-screen block: that window is
+opened with `window.open('')` and never fetched the linked stylesheet, so they
+were overriding something that never arrived. `SecondaryDisplay.tsx` now inlines
+the rules and adopts the already-loaded font faces.
+
+Contrast is measured with a gradient-aware checker across six workspaces in both
+modes; the threshold is WCAG AA.
+
+## Loading strategy
+
+The workbench is a separate chunk behind `React.lazy`. The sign-in screen loads
+344 kB over the wire instead of 1.46 MB.
+
+`apiGet` shares concurrent and closely-following identical requests for 300 ms.
+This collapses the start-up cascade, where two effects asked for the same areas
+and datasets about ninety milliseconds apart. The table is cleared on sign-in,
+sign-out and session expiry, because signing out does not reload the page.
+
+Each workspace loads its own data when it is first opened rather than everything
+up front. Start-up went from 27 requests to 16.
+
+Source images for the web assets live in `design-assets/`, not in `public/`.
+Everything in `public/` is copied verbatim into `dist/`, so 8.1 MB of unused PNG
+masters shipped with every build.