fix: clear missing media errors when widget value changes on node

Add removeMissingMediaByWidget to missingMediaStore and call it from
clearWidgetRelatedErrors, matching the existing missing model pattern.
When a user changes a media widget value directly on a node, the
corresponding missing media error is removed from the error tab.

src/platform/missingMedia/missingMediaStore.test.ts

@@ -102,6 +102,38 @@ describe('useMissingMediaStore', () => {
     expect(store.hasMissingMediaOnNode('99')).toBe(false)
   })
 
+  it('removeMissingMediaByWidget removes matching node+widget entry', () => {
+    const store = useMissingMediaStore()
+    store.setMissingMedia([
+      makeCandidate('1', 'photo.png'),
+      makeCandidate('2', 'clip.mp4', 'video')
+    ])
+
+    store.removeMissingMediaByWidget('1', 'image')
+
+    expect(store.missingMediaCandidates).toHaveLength(1)
+    expect(store.missingMediaCandidates![0].name).toBe('clip.mp4')
+  })
+
+  it('removeMissingMediaByWidget nulls candidates when last entry removed', () => {
+    const store = useMissingMediaStore()
+    store.setMissingMedia([makeCandidate('1', 'photo.png')])
+
+    store.removeMissingMediaByWidget('1', 'image')
+
+    expect(store.missingMediaCandidates).toBeNull()
+    expect(store.hasMissingMedia).toBe(false)
+  })
+
+  it('removeMissingMediaByWidget ignores non-matching entries', () => {
+    const store = useMissingMediaStore()
+    store.setMissingMedia([makeCandidate('1', 'photo.png')])
+
+    store.removeMissingMediaByWidget('99', 'image')
+
+    expect(store.missingMediaCandidates).toHaveLength(1)
+  })
+
   it('createVerificationAbortController aborts previous controller', () => {
     const store = useMissingMediaStore()
     const first = store.createVerificationAbortController()

src/platform/missingMedia/missingMediaStore.ts

@@ -97,6 +97,15 @@ export const useMissingMediaStore = defineStore('missingMedia', () => {
       missingMediaCandidates.value = null
   }
 
+  function removeMissingMediaByWidget(nodeId: string, widgetName: string) {
+    if (!missingMediaCandidates.value) return
+    missingMediaCandidates.value = missingMediaCandidates.value.filter(
+      (m) => !(String(m.nodeId) === nodeId && m.widgetName === widgetName)
+    )
+    if (!missingMediaCandidates.value.length)
+      missingMediaCandidates.value = null
+  }
+
   function clearMissingMedia() {
     _verificationAbortController?.abort()
     _verificationAbortController = null
@@ -116,6 +125,7 @@ export const useMissingMediaStore = defineStore('missingMedia', () => {
 
     setMissingMedia,
     removeMissingMediaByName,
+    removeMissingMediaByWidget,
     clearMissingMedia,
     createVerificationAbortController,
 

src/stores/executionErrorStore.ts

@@ -160,6 +160,7 @@ export const useExecutionErrorStore = defineStore('executionError', () => {
       options
     )
     missingModelStore.removeMissingModelByWidget(executionId, widgetName)
+    missingMediaStore.removeMissingMediaByWidget(executionId, widgetName)
   }
 
   /** Set missing models and open the error overlay if the Errors tab is enabled. */