Set the selected still on Use image instead of an empty Photos card.

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

components/studio2/Bench.vue

@@ -232,8 +232,8 @@
        class="stage-actions"
        aria-label="Selected still actions"
       >
-       <button type="button" @click="applyUseImage">Use image</button>
-       <button type="button" @click="applyUsePrompt">Use prompt</button>
+       <button type="button" @click="applyUseImage()">Use image</button>
+       <button type="button" @click="applyUsePrompt()">Use prompt</button>
        <div class="stage-split">
         <button
          type="button"
@@ -895,6 +895,11 @@ function sourceStillIdsOf(item:any){
  if(meta.imageBId) push(meta.imageBId)
  return ids.filter(id=>stillById(id))
 }
+function resolveActionAsset(item?:any){
+ // Stage @click handlers pass a MouseEvent as the first arg — never treat events as library assets.
+ if(item && typeof item.id==='string' && item.id) return item
+ return selected.value
+}
 function useImageRole(){
  const plan=photosPlanState.value
  const filled=(form.photos||[]).filter((p:any)=>p?.stillId)
@@ -904,36 +909,61 @@ function useImageRole(){
  return plan.defaultRole || 'change'
 }
 function applyUseImage(item?:any){
- const asset=item || selected.value
- if(!asset||asset.kind==='track')return
+ const asset=resolveActionAsset(item)
+ if(!asset?.id){
+  uploadMessage.value='Select a still first.'
+  return
+ }
+ if(asset.kind==='track' || asset.kind==='clip'){
+  uploadMessage.value='Use image needs a still.'
+  return
+ }
+ const stillId=String(asset.id)
+ if(!stillById(stillId)){
+  uploadMessage.value='Select a still first.'
+  return
+ }
  const plan=photosPlanState.value
  const role=useImageRole()
- if(!plan.show){
-  form.photos=[{stillId:asset.id,role}]
+ // Prefer filling an empty draft card left by + Add photo; never open the picker.
+ const emptyIdx=(form.photos||[]).findIndex((p:any)=>!p?.stillId)
+ if(emptyIdx>=0){
+  form.photos[emptyIdx]={stillId,role}
   syncPhotosBindings()
   uploadMessage.value=`Added ${assetLabel(asset)} to Photos.`
   saveBenchDraft(true)
   return
  }
- if(form.photos.length>=plan.max){
-  form.photos[form.photos.length-1]={stillId:asset.id,role}
- }else{
-  form.photos.push({stillId:asset.id,role})
+ if(plan.show && !plan.handoffReadonly && (form.photos||[]).length>=plan.max){
+  const changeIdx=(form.photos||[]).findIndex((p:any)=>p?.role==='change')
+  if(changeIdx>=0){
+   form.photos[changeIdx]={stillId,role:'change'}
+   syncPhotosBindings()
+   uploadMessage.value=`Replaced Photos card with ${assetLabel(asset)}.`
+   saveBenchDraft(true)
+   return
   }
+  uploadMessage.value='Photos full.'
+  return
+ }
+ form.photos.push({stillId,role})
  syncPhotosBindings()
  uploadMessage.value=`Added ${assetLabel(asset)} to Photos.`
  saveBenchDraft(true)
 }
 function applyUsePrompt(item?:any){
- const asset=item || selected.value
- if(!asset)return
+ const asset=resolveActionAsset(item)
+ if(!asset){
+  uploadMessage.value='Select a still first.'
+  return
+ }
  const text=usedPromptOf(asset)
  form.promptSections.action=text
  uploadMessage.value=text?'Prompt set from this item.':'No Used prompt on this item.'
  saveBenchDraft(true)
 }
 async function copySelectedPrompt(item?:any){
- const asset=item || selected.value
+ const asset=resolveActionAsset(item)
  const text=usedPromptOf(asset)
  try{
   if(import.meta.client && navigator.clipboard)await navigator.clipboard.writeText(String(text||''))
@@ -941,7 +971,7 @@ async function copySelectedPrompt(item?:any){
  }catch{error.value='Could not copy prompt.'}
 }
 async function copySelectedRawPrompt(item?:any){
- const asset=item || selected.value
+ const asset=resolveActionAsset(item)
  const raw=rawPromptOf(asset)
  const used=usedPromptOf(asset)
  const text=raw || used
@@ -961,8 +991,11 @@ function loadInputPhotos(ids:string[]){
  syncPhotosBindings()
 }
 function loadInputUsed(item?:any){
- const asset=item || selected.value
- if(!asset)return
+ const asset=resolveActionAsset(item)
+ if(!asset){
+  uploadMessage.value='Select a still first.'
+  return
+ }
  const ids=sourceStillIdsOf(asset)
  const text=usedPromptOf(asset)
  if(ids.length) loadInputPhotos(ids)
@@ -973,8 +1006,11 @@ function loadInputUsed(item?:any){
  saveBenchDraft(true)
 }
 function loadInputRaw(item?:any){
- const asset=item || selected.value
- if(!asset)return
+ const asset=resolveActionAsset(item)
+ if(!asset){
+  uploadMessage.value='Select a still first.'
+  return
+ }
  const ids=sourceStillIdsOf(asset)
  const raw=rawPromptOf(asset)
  const used=usedPromptOf(asset)