Preserve animated zoom across semantic LOD transitions

.agents/inbox/2026-10-27-lod-title-refresh-must-not-own-camera.md

@@ -0,0 +1,65 @@
+# LOD title refresh must not interrupt the owning camera transition
+
+Date: 2026-10-27. Issue #205. The symptom index already covered explicit camera
+input cancelling automatic framing and renderer ownership; neither addressed an
+overview-exit title refresh interrupting the active user animation.
+
+## Evidence
+
+CSS PR #199 CI run `40591493014` failed the desktop semantic-LOD case at camera
+scale `1.1735656098434863` while expecting `1.2`. Its retained trace shows this
+was after the test clock resumed; it was not an unadvanced-clock failure.
+
+A new production-renderer regression starts at `1.1`, requests the existing
+120 ms minimap zoom to `1.2`, and advances twelve 16 ms frames. It explicitly
+observes overview exit above `1.15` before the target is reached. On the original
+runtime, `npm run qc:lod -- --grep 1440 --trace=retain-on-failure` failed with
+`1.1767031700493764` instead of `1.2`. The trace is retained under the owned
+`/tmp/graphdone-resolution-20261027/lod-transition-negative-artifacts` directory.
+
+The corrected runtime passes both 301-node/370-edge desktop and phone LOD
+journeys in 3.3 minutes with one worker and zero retries. Existing membership,
+label geometry, selected-item navigation, graph switching and zero-position-write
+checks remain. Build, typecheck and lint pass (existing lint warnings remain);
+web tests pass 346/346 and the harness passes 175/175. Exact-head review and CI
+remain required before integration; source-only evidence is not a live deployment.
+
+## Cause and corrective rule
+
+The overview-exit effect reapplied the current camera through
+`zoomBehavior.transform` to make formerly hidden title elements measurable.
+D3's selection form of that API interrupts the selection's active transition.
+Thus a presentation refresh cancelled the same animation that crossed the LOD
+threshold, saving an intermediate camera position.
+
+Refresh source-title geometry directly using the live camera scale after source
+elements become visible. Scope the selection to the source `.main-graph-group`, retain
+the same-graph transition guard, and respect simplified rendering. Do not emit a
+camera command merely to refresh presentation. Camera transitions belong to the
+navigation operation that initiated them.
+
+## A live renderer selector needs its own observation
+
+Follow-up review found the initial title-only change used `.main-group`, while
+both renderer initializers create `.main-graph-group`. The effect was therefore
+a no-op. Animated zoom still passed because later frames refitted the titles.
+An initial fixed-camera geometry-only check also passed; neither result proved
+the explicit refresh actually ran. These passing-but-insufficient controls are
+retained rather than presented as a negative control.
+
+The strengthened fixed-camera Overview→Items phase instruments the selected
+real SVG title's native `getBBox` method, retaining its actual geometry result.
+It requires a visible measurement, bounded title geometry, an identical camera
+and zero minimap camera publications, with the animation clock paused. The
+incorrect selector fails with zero visible measurements. With the actual source
+selector, both desktop and phone cases pass in 4.2 minutes with zero retries;
+the source selector
+must be taken from the actual renderer. Do not infer presentation work occurred
+merely because an animation reached its target.
+
+## Limits
+
+This corrects overview-to-item transition ownership; it does not implement the
+remaining multilevel grouping, bounded 1k rendering or progressive 10k loading
+milestones. The browser regression uses owned synthetic graphs and preserves the
+original interaction deadlines, required assertions and strict fixture cleanup.

.agents/issues/INDEX.md

@@ -2,6 +2,7 @@
 
 | Symptom | Canonical lesson and regression |
 | --- | --- |
+| Animated zoom stops near the overview exit threshold instead of reaching its target | [Title refresh must not own the camera](../inbox/2026-10-27-lod-title-refresh-must-not-own-camera.md); frame-controlled `semantic-lod.spec.ts` negative control |
 | Disposable Git fixture teardown reports ENOTEMPTY under .git after a synchronous commit | [Prevent detached fixture maintenance](../inbox/2026-10-27-disposable-git-fixtures-must-own-maintenance.md); `tests/lib/runner/unified-cli.test.mjs` |
 | A router major update passes install but path handling or route UI assertions differ | [Validate installed navigation and current UI contracts](../inbox/2026-10-27-router-upgrades-need-current-consumer-contracts.md); `routerNavigation.test.tsx`, `router-navigation.spec.ts`, dependency guard |
 | Status-note text lands in the title and Add remains disabled after quick edit opens | [Delayed autofocus must preserve chosen focus](../inbox/2026-10-27-delayed-autofocus-must-preserve-chosen-focus.md); `QuickEditSurface.test.tsx` controls the pending frame |

packages/web/src/components/InteractiveGraphVisualization.tsx

@@ -4316,8 +4316,11 @@ export function InteractiveGraphVisualization({ onResetLayout, onNodeSelected, i
     // that would persist an unfitted/default (or previous graph's) camera.
     const previous = previousOverview.current;
     previousOverview.current = { active: semanticOverviewActive, graphId: currentGraph?.id };
-    if (previous.active && previous.graphId === currentGraph?.id && !semanticOverviewActive && svgRef.current && zoomBehaviorRef.current) {
-      d3.select(svgRef.current).call(zoomBehaviorRef.current.transform, d3.zoomTransform(svgRef.current));
+    if (previous.active && previous.graphId === currentGraph?.id && !semanticOverviewActive && svgRef.current && !simplifiedRef.current) {
+      const k = d3.zoomTransform(svgRef.current).k;
+      d3.select(svgRef.current).select('.main-graph-group')
+        .selectAll<SVGGElement, unknown>('.node-title-group')
+        .attr('transform', function() { return fittedTitleTransform(this, k); });
     }
   }, [semanticOverviewActive, currentGraph?.id]);
 

tests/e2e/graph/semantic-lod.spec.ts

@@ -199,6 +199,72 @@ for (const width of [1440, 390])
           (element as SVGSVGElement & { __zoom: { k: number } }).__zoom.k
         )).toBeCloseTo(0.5);
       }
+      await zoomToTitle(1.1, true);
+      await page.evaluate(({ x, y }) => {
+        (window as unknown as { miniMapZoom: (x: number, y: number, k: number) => void }).miniMapZoom(x, y, 1.2);
+      }, { x: longTitleItem.positionX, y: longTitleItem.positionY });
+      let exitedBeforeTarget = false;
+      for (let frame = 0; frame < 12; frame++) {
+        await page.clock.runFor(16);
+        const k = await svg.evaluate(element =>
+          (element as SVGSVGElement & { __zoom: { k: number } }).__zoom.k
+        );
+        if (k > 1.15 && k < 1.2 && await overview.getAttribute('data-active') === 'false') exitedBeforeTarget = true;
+      }
+      expect(exitedBeforeTarget).toBe(true);
+      expect(await svg.evaluate(element =>
+        (element as SVGSVGElement & { __zoom: { k: number } }).__zoom.k
+      )).toBeCloseTo(1.2);
+      await expect(overview).toHaveAttribute('data-active', 'false');
+      await zoomToTitle(0.5, true);
+      await expect(overview).toHaveAttribute('data-active', 'true');
+      const fixedCamera = await svg.evaluate(element => {
+        const camera = (element as SVGSVGElement & { __zoom: { x: number; y: number; k: number } }).__zoom;
+        return { x: camera.x, y: camera.y, k: camera.k };
+      });
+      await page.evaluate(id => {
+        const target = window as any;
+        const node = Array.from(document.querySelectorAll('.main-graph-group .node')).find(element => (element as any).__data__?.id === id)!;
+        const title = node.querySelector('.node-title-group') as SVGGElement;
+        const measure = title.getBBox.bind(title);
+        target.__lodVisibleTitleMeasurements = 0;
+        target.__lodRestoreTitleMeasurement = () => { delete (title as any).getBBox; };
+        title.getBBox = () => {
+          if (!title.closest('[data-overview="true"]')) target.__lodVisibleTitleMeasurements++;
+          return measure();
+        };
+        target.__lodCameraRefreshCount = 0;
+        target.__lodOriginalViewportUpdate = target.updateMiniMapViewport;
+        target.updateMiniMapViewport = (...args: unknown[]) => {
+          target.__lodCameraRefreshCount++;
+          return target.__lodOriginalViewportUpdate?.(...args);
+        };
+      }, seeded.nodeIds[8]);
+      await overview.getByRole('combobox', { name: 'Graph detail' }).selectOption('items');
+      await expect(overview).toHaveAttribute('data-active', 'false');
+      await expect.poll(() => svg.locator('.main-graph-group .node').evaluateAll((elements, id) => {
+        const node = elements.find(element => (element as Element & { __data__?: { id: string } }).__data__?.id === id)!;
+        const title = node.querySelector('.node-title-group')!.getBoundingClientRect();
+        const card = node.querySelector('.node-bg')!.getBoundingClientRect();
+        return title.width > 0 && title.left >= card.left && title.right <= card.right && title.top >= card.top && title.bottom <= card.bottom;
+      }, seeded.nodeIds[8])).toBe(true);
+      expect(await svg.evaluate(element => {
+        const camera = (element as SVGSVGElement & { __zoom: { x: number; y: number; k: number } }).__zoom;
+        return { x: camera.x, y: camera.y, k: camera.k };
+      })).toEqual(fixedCamera);
+      await expect.poll(() => page.evaluate(() => (window as any).__lodVisibleTitleMeasurements)).toBeGreaterThan(0);
+      expect(await page.evaluate(() => (window as any).__lodCameraRefreshCount)).toBe(0);
+      await page.evaluate(() => {
+        const target = window as any;
+        target.updateMiniMapViewport = target.__lodOriginalViewportUpdate;
+        delete target.__lodOriginalViewportUpdate;
+        delete target.__lodCameraRefreshCount;
+        target.__lodRestoreTitleMeasurement();
+        delete target.__lodRestoreTitleMeasurement;
+        delete target.__lodVisibleTitleMeasurements;
+      });
+      await overview.getByRole('combobox', { name: 'Graph detail' }).selectOption('auto');
+      await expect(overview).toHaveAttribute('data-active', 'true');
       await page.clock.resume();
       const geometry = await overviewGeometry();
       await info.attach('overview-geometry.json', {