1.1.5: settings/media folder details + empty-click deselects everything

- Settings → Media tab now shows per-folder image/audio counts, skipped
  subfolders, skipped files, and a rescan button. listClipart hard-skips
  subdirectories and unsupported file extensions, returning a skip
  report the panel renders.
- Empty-click anywhere — chrome, bare stage, empty timeline tracks —
  clears the full selection (layers, clip instances, keyframes) via a
  shared useDeselectAll helper. shouldChromeClickDeselect() splits
  exclusions into interactive elements, overlays, editing panels and
  timeline selection elements so empty timeline space deselects too.

src/composables/useDeselectAll.ts

@@ -0,0 +1,17 @@
+import { useKfSelection } from '@/composables/useKfSelection'
+import { useSceneStore } from '@/stores/scene'
+
+/** Clear every selection-like piece of UI state in one shot — layers,
+ *  clip instances, and timeline keyframes. Called from every "empty
+ *  click" surface (chrome, empty stage, empty timeline) so the gesture
+ *  carries the same meaning everywhere instead of each surface only
+ *  clearing its own slice. */
+export function useDeselectAll() {
+  const store = useSceneStore()
+  const { selectedKfs } = useKfSelection()
+  return function deselectAll() {
+    store.selectLayer(null)
+    store.selectClipInstance(null)
+    selectedKfs.value = []
+  }
+}