Bug

In the app viewer, with multiple accordions stacked vertically, collapsing all of them still leaves the canvas at its original (fully-expanded) height — the page stays scrollable with a large empty white area below the collapsed accordions.

Root cause

updateCanvasBottomHeight in `frontend/src/AppBuilder/_stores/slices/appSlice.js` computed the scroll height as:

```js
const maxHeight = Math.max(maxPermanentHeight, temporaryLayoutsMaxHeight);
```

• `maxPermanentHeight` is derived from each component's static authored `layout.top + layout.height`.
• `temporaryLayoutsMaxHeight` is derived from the reflowed `temporaryLayouts`.

Collapsing an accordion triggers dynamic-height reflow (`useDynamicHeight` → `adjustComponentPositions` → `dynamicHeightReflow.js`), which shrinks the widget and shifts siblings up — but writes the new positions only to `temporaryLayouts`, never to the permanent `layouts`. So the temp max drops while the permanent max stays at the original expanded bottom, and `Math.max` keeps the canvas tall.

Fix

Unify into a single pass using the effective layout per component (`temporaryLayouts[id] ?? layouts[currentLayout]`) so a reflowed/collapsed widget correctly lowers the canvas bottom.

Note: only affects accordions/widgets with dynamic height enabled (otherwise siblings don't reflow on collapse by design).