[refactor] Unify Cloud/OSS Missing Nodes modal (#6673)

## Summary
- Merged separate Cloud and OSS workflow warning modals into single
unified modal
- Removed legacy LoadWorkflowWarning.vue
- Renamed CloudMissingNodes* components to MissingNodes* for clarity
- Environment branching now handled internally via isCloud flag
- Restructured i18n: removed loadWorkflowWarning, added
missingNodes.cloud/oss sections
- Improved OSS button styling to match Cloud consistency

## Key Changes
- **OSS**: "Open Manager" + "Install All" buttons
- **Cloud**: "Learn More" + "Got It" buttons (unchanged)
- Single unified modal displays different UI/text based on environment

## 📝 Note on File Renames

This PR renames the following files:

- `CloudMissingNodesHeader.vue` → `MissingNodesHeader.vue` (R053, 53%
similarity)
- `CloudMissingNodesContent.vue` → `MissingNodesContent.vue` (R067, 67%
similarity)
- `LoadWorkflowWarning.vue` → `MissingNodesFooter.vue` (R051, 51%
similarity)
- `CloudMissingNodesFooter.vue` → Deleted (replaced by new
MissingNodesFooter)

**Why GitHub PR UI doesn't show renames properly:**

GitHub detects renames only when file similarity is above 70%. In this
PR, the Cloud/OSS unification significantly modified file contents,
resulting in 51-67% similarity.

However, **Git history correctly records these as renames**. You can
verify with:

```bash
git show <commit-hash> --name-status
```

While GitHub UI shows "additions/deletions", these are actually rename +
modification operations.

## Test Plan
- [x] Test OSS mode: missing nodes modal shows "Open Manager" and
"Install All" buttons
- [x] Test Cloud mode: missing nodes modal shows "Learn More" and "Got
It" buttons
- [x] Verify Install All button functionality in OSS
- [x] Verify modal closes automatically after all nodes are installed
(OSS)


[missingnodes.webm](https://github.com/user-attachments/assets/36d3b4b0-ff8b-4b45-824c-3bc15d93f1a2)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6673-refactor-Unify-Cloud-OSS-Missing-Nodes-modal-2aa6d73d365081a88827d0fa85db4c63)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Claude <noreply@anthropic.com>

src/services/dialogService.ts

@@ -2,12 +2,11 @@ import { merge } from 'es-toolkit/compat'
 import type { Component } from 'vue'
 
 import ApiNodesSignInContent from '@/components/dialog/content/ApiNodesSignInContent.vue'
-import CloudMissingNodesContent from '@/components/dialog/content/CloudMissingNodesContent.vue'
-import CloudMissingNodesFooter from '@/components/dialog/content/CloudMissingNodesFooter.vue'
-import CloudMissingNodesHeader from '@/components/dialog/content/CloudMissingNodesHeader.vue'
+import MissingNodesContent from '@/components/dialog/content/MissingNodesContent.vue'
+import MissingNodesFooter from '@/components/dialog/content/MissingNodesFooter.vue'
+import MissingNodesHeader from '@/components/dialog/content/MissingNodesHeader.vue'
 import ConfirmationDialogContent from '@/components/dialog/content/ConfirmationDialogContent.vue'
 import ErrorDialogContent from '@/components/dialog/content/ErrorDialogContent.vue'
-import LoadWorkflowWarning from '@/components/dialog/content/LoadWorkflowWarning.vue'
 import MissingModelsWarning from '@/components/dialog/content/MissingModelsWarning.vue'
 import PromptDialogContent from '@/components/dialog/content/PromptDialogContent.vue'
 import SignInContent from '@/components/dialog/content/SignInContent.vue'
@@ -47,24 +46,15 @@ export type ConfirmationDialogType =
 
 export const useDialogService = () => {
   const dialogStore = useDialogStore()
-  function showLoadWorkflowWarning(
-    props: InstanceType<typeof LoadWorkflowWarning>['$props']
-  ) {
-    dialogStore.showDialog({
-      key: 'global-load-workflow-warning',
-      component: LoadWorkflowWarning,
-      props
-    })
-  }
 
-  function showCloudLoadWorkflowWarning(
-    props: ComponentProps<typeof CloudMissingNodesContent>
+  function showLoadWorkflowWarning(
+    props: ComponentProps<typeof MissingNodesContent>
   ) {
     dialogStore.showDialog({
-      key: 'global-cloud-missing-nodes',
-      headerComponent: CloudMissingNodesHeader,
-      footerComponent: CloudMissingNodesFooter,
-      component: CloudMissingNodesContent,
+      key: 'global-missing-nodes',
+      headerComponent: MissingNodesHeader,
+      footerComponent: MissingNodesFooter,
+      component: MissingNodesContent,
       dialogComponentProps: {
         closable: true,
         pt: {
@@ -550,7 +540,6 @@ export const useDialogService = () => {
 
   return {
     showLoadWorkflowWarning,
-    showCloudLoadWorkflowWarning,
     showMissingModelsWarning,
     showSettingsDialog,
     showAboutDialog,