feat: detect and resolve missing media inputs in error tab (#10309)

## Summary

Add detection and resolution UI for missing image/video/audio inputs
(LoadImage, LoadVideo, LoadAudio nodes) in the Errors tab, mirroring the
existing missing model pipeline.

## Changes

- **What**: New `src/platform/missingMedia/` module — scan pipeline
detects missing media files on workflow load (sync for OSS, async for
cloud), surfaces them in the error tab with upload dropzone, thumbnail
library select, and 2-step confirm flow
- **Detection**: `scanAllMediaCandidates()` checks combo widget values
against options; cloud path defers to `verifyCloudMediaCandidates()` via
`assetsStore.updateInputs()`
- **UI**: `MissingMediaCard` groups by media type; `MissingMediaRow`
shows node name (single) or filename+count (multiple), upload dropzone
with drag & drop, `MissingMediaLibrarySelect` with image/video
thumbnails
- **Resolution**: Upload via `/upload/image` API or select from library
→ status card → checkmark confirm → widget value applied, item removed
from error list
- **Integration**: `executionErrorStore` aggregates into
`hasAnyError`/`totalErrorCount`; `useNodeErrorFlagSync` flags nodes on
canvas; `useErrorGroups` renders in error tab
- **Shared**: Extract `ACCEPTED_IMAGE_TYPES`/`ACCEPTED_VIDEO_TYPES` to
`src/utils/mediaUploadUtil.ts`; extract `resolveComboValues` to
`src/utils/litegraphUtil.ts` (shared across missingMedia + missingModel
scan)
- **Reverse clearing**: Widget value changes on nodes auto-remove
corresponding missing media errors (via `clearWidgetRelatedErrors`)

## Testing

### Unit tests (22 tests)
- `missingMediaScan.test.ts` (12): groupCandidatesByName,
groupCandidatesByMediaType (ordering, multi-name),
verifyCloudMediaCandidates (missing/present, abort before/after
updateInputs, already resolved true/false, no-pending skip, updateInputs
spy)
- `missingMediaStore.test.ts` (10): setMissingMedia, clearMissingMedia
(full lifecycle with interaction state), missingMediaNodeIds,
hasMissingMediaOnNode, removeMissingMediaByWidget
(match/no-match/last-entry), createVerificationAbortController

### E2E tests (10 scenarios in `missingMedia.spec.ts`)
- Detection: error overlay shown, Missing Inputs group in errors tab,
correct row count, dropzone + library select visibility, no false
positive for valid media
- Upload flow: file picker → uploading status card → confirm → row
removed
- Library select: dropdown → selected status card → confirm → row
removed
- Cancel: pending selection → returns to upload/library UI
- All resolved: Missing Inputs group disappears
- Locate node: canvas pans to missing media node

## Review Focus

- Cloud verification path: `verifyCloudMediaCandidates` compares widget
value against `asset_hash` — implicit contract
- 2-step confirm mirrors missing model pattern (`pendingSelection` →
confirm/cancel)
- Event propagation guard on dropzone (`@drop.prevent.stop`) to prevent
canvas LoadImage node creation
- `clearAllErrors()` intentionally does NOT clear missing media (same as
missing models — preserves pending repairs)
- `runMissingMediaPipeline` is now `async` and `await`-ed, matching
model pipeline

## Test plan

- [x] OSS: load workflow with LoadImage referencing non-existent file →
error tab shows it
- [x] Upload file via dropzone → status card shows "Uploaded" → confirm
→ widget updated, error removed
- [x] Select from library with thumbnail preview → confirm → widget
updated, error removed
- [x] Cancel pending selection → returns to upload/library UI
- [x] Load workflow with valid images → no false positives
- [x] Click locate-node → canvas navigates to the node
- [x] Multiple nodes referencing different missing files → correct row
count
- [x] Widget value change on node → missing media error auto-removed

## Screenshots


https://github.com/user-attachments/assets/631c0cb0-9706-4db2-8615-f24a4c3fe27d

src/platform/missingModel/missingModelScan.ts

@@ -22,6 +22,7 @@ import {
   collectAllNodes,
   getExecutionIdByNode
 } from '@/utils/graphTraversalUtil'
+import { resolveComboValues } from '@/utils/litegraphUtil'
 
 function isComboWidget(widget: IBaseWidget): widget is IComboWidget {
   return widget.type === 'combo'
@@ -50,14 +51,6 @@ export function isModelFileName(name: string): boolean {
   return Array.from(MODEL_FILE_EXTENSIONS).some((ext) => lower.endsWith(ext))
 }
 
-function resolveComboOptions(widget: IComboWidget): string[] {
-  const values = widget.options.values
-  if (!values) return []
-  if (typeof values === 'function') return values(widget)
-  if (Array.isArray(values)) return values
-  return Object.keys(values)
-}
-
 /**
  * Scan COMBO and asset widgets on configured graph nodes for model-like values.
  * Must be called after `graph.configure()` so widget name/value mappings are accurate.
@@ -139,7 +132,7 @@ function scanComboWidget(
   if (!isModelFileName(value)) return null
 
   const nodeIsAssetSupported = isAssetSupported(node.type, widget.name)
-  const options = resolveComboOptions(widget)
+  const options = resolveComboValues(widget)
   const inOptions = options.includes(value)
 
   return {