Merge origin/main into feat/placement-interaction-overhaul

Resolve 7 conflicts keeping our snapping migration + floorplan perf work as
source of truth, combined with main's MEP run-continuation / Alt-detach /
latch handles. Rebuilt two import blocks the auto-merge silently truncated
(node-arrow-handles.tsx, duct-fitting/move-tool.tsx).

Verified: tsc clean across core/viewer/editor/nodes/mcp, 451 tests pass,
biome clean. Floorplan view-transform re-render storm confirmed pre-existing
(not introduced by this merge).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/nodes/src/window/definition.ts

@@ -43,6 +43,9 @@ function windowWidthHandle(side: 'left' | 'right'): HandleDescriptor<WindowNodeT
   return {
     kind: 'linear-resize',
     axis: 'x',
+    // Stand the blade up into the wall face so it reads face-on from the
+    // front instead of edge-on (the window sits on a vertical wall).
+    faceNormal: true,
     anchor: side === 'right' ? 'min' : 'max',
     min: MIN_WINDOW_WIDTH,
     max: (n, scene) => {