Copy generated stills into Input without loading the current frame.

Co-authored-by: Cursor <cursoragent@cursor.com>

pages/library.vue

@@ -245,6 +245,13 @@
           <div class="mt-4 flex flex-wrap gap-2">
             <button type="button" class="rounded-full border border-amber-300/40 px-3 py-1.5 text-xs text-amber-100" @click="openInStudio(focused)">Open in Studio</button>
             <button type="button" class="rounded-full border border-white/10 px-3 py-1.5 text-xs text-zinc-300 hover:text-white" @click="useInStudio(focused)">Use as input</button>
+            <button
+              v-if="focused.kind === 'still' && focusedStillRole !== 'input'"
+              type="button"
+              class="rounded-full border border-white/10 px-3 py-1.5 text-xs text-zinc-300 hover:text-white"
+              :disabled="keepingInputBusy"
+              @click="saveFocusedAsInput"
+            >{{ keepingInputBusy ? 'Saving…' : 'Save as input' }}</button>
             <a
               v-if="downloadHref"
               :href="downloadHref"
@@ -374,6 +381,7 @@ const renameInput = ref<HTMLInputElement | null>(null)
 const deleteBusy = ref(false)
 const detailsHidden = ref(false)
 const pendingDelete = ref<{ title: string; name: string; detail?: string; consequence: string; keys: string[] } | null>(null)
+const keepingInputBusy = ref(false)
 const toasts = ref<Array<{ id: number; message: string }>>([])
 let toastId = 0
 let searchTimer: ReturnType<typeof setTimeout> | null = null
@@ -420,6 +428,11 @@ const folderChipCounts = computed(() => {
 })
 const moveFolders = computed(() => folders.value.filter(folder => folder.id !== folderId.value))
 const focused = computed(() => entries.value.find(entry => entry.key === focusedKey.value) || null)
+const focusedStill = computed(() => {
+  if (focused.value?.kind !== 'still' || !focused.value.stillGroup) return null
+  return focused.value.stillGroup.parts.find(part => part.id === focusedPartId.value) || focused.value.stillGroup.head
+})
+const focusedStillRole = computed(() => focusedStill.value?.role === 'input' ? 'input' : (focusedStill.value ? (focusedStill.value.role || 'output') : ''))
 const emptyLabel = computed(() => {
   if (search.value.trim()) return 'Nothing matches that search.'
   if (filter.value === 'images') return 'No generated stills here yet.'
@@ -716,6 +729,20 @@ function useInStudio(entry: LibraryEntry) {
   }
 }
 
+async function saveFocusedAsInput() {
+  const still = focusedStill.value
+  if (!still || keepingInputBusy.value) return
+  keepingInputBusy.value = true
+  try {
+    applyLibrary(await $fetch(`/api/library/stills/${still.id}/keep-input`, { method: 'POST' }))
+    toast('Saved to Input. Pick it later from Choose an image → Input.')
+  } catch (error: any) {
+    toast(error?.data?.statusMessage || 'Could not save that still as input')
+  } finally {
+    keepingInputBusy.value = false
+  }
+}
+
 function startRename() {
   if (!focused.value) return
   renaming.value = true