0.17.0: split SVG layer into per-path layers

Right-click an SVG-backed layer to split it into one layer per
top-level drawable. Each part keeps the original stage position
and ends up as a same-size standalone SVG.

Also: delete confirm now floats above the welcome dialog (topmost
z-index + scoped ESC/Tab via modal stack) and autofocuses its
primary button so Enter triggers confirm instead of bubbling back
to the underlying row.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/Timeline.vue

@@ -24,6 +24,7 @@ import {
   PhPencilSimpleLine,
   PhPlus,
   PhPolygon,
+  PhScissors,
   PhSpeakerSlash,
   PhSquare,
   PhTextT,
@@ -2683,6 +2684,26 @@ function convertSelectedToClipFromMenu() {
   trackMenu.value = null
 }
 
+/** True only for a context-menu tied to an SVG-backed image layer.
+ *  Gates the "Split SVG" entry so the menu doesn't show a dead action
+ *  on raster layers. */
+const canSplitSvgFromMenu = computed(() => {
+  const m = trackMenu.value
+  if (!m || m.kind !== 'layer') return false
+  const layer = store.scene.layers.find((l) => l.id === m.trackId)
+  if (!layer) return false
+  const asset = store.scene.assets.find((a) => a.id === layer.assetId)
+  if (!asset || asset.kind !== 'image') return false
+  return asset.src.startsWith('data:image/svg+xml')
+})
+
+function splitSvgFromMenu() {
+  const m = trackMenu.value
+  if (!m || m.kind !== 'layer') return
+  store.splitLayerSvg(m.trackId)
+  trackMenu.value = null
+}
+
 function deleteTrack() {
   if (!trackMenu.value) return
   if (trackMenu.value.kind === 'layer') {
@@ -3976,6 +3997,15 @@ onBeforeUnmount(() => {
             <PhFilmStrip :size="12" class="kf-menu-icon" />
             {{ t('timeline.convertToClip', { n: store.selectedLayerIds.length }) }}
           </button>
+          <button
+            v-if="canSplitSvgFromMenu"
+            class="kf-menu-item"
+            :disabled="trackMenu.locked"
+            @click="splitSvgFromMenu"
+          >
+            <PhScissors :size="12" class="kf-menu-icon" />
+            {{ t('timeline.splitSvg') }}
+          </button>
         </template>
       </template>
       <template v-if="trackMenu.kind !== 'group'">