Even further app fixes (#9617)

- Allow dragging zoom pane with middle click
- Prevent selection of canvasOnly widgets
- These widgets would not display in app mode, so allow selection would
only cause confusion.
- Support displaying the error dialogue in app mode
- Add a somewhat involved mobile app mode error indication system
<img width="300" alt="image"
src="https://github.com/user-attachments/assets/d8793bbd-fff5-4b2a-a316-6ff154bae2c4"
/> <img width="300" alt="image"
src="https://github.com/user-attachments/assets/cb88b0f6-f7e5-409e-ae43-f1348f946b19"
/>

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9617-Even-further-app-fixes-31d6d73d365081c891dfdfe3477cfd61)
by [Unito](https://www.unito.io)

src/locales/en/main.json

@@ -3180,6 +3180,7 @@
     "cancelThisRun": "Cancel this run",
     "deleteAllAssets": "Delete all assets from this run",
     "hasCreditCost": "Requires additional credits",
+    "viewGraph": "View node graph",
     "welcome": {
       "title": "App Mode",
       "message": "A simplified view that hides the node graph so you can focus on creating.",
@@ -3224,6 +3225,19 @@
       "outputPlaceholder": "Output nodes will show up here",
       "outputRequiredPlaceholder": "At least one node is required"
     },
+    "error": {
+      "header": "This app encountered an error",
+      "log": "Error Logs",
+      "mobileFixable": "Check {0} for errors",
+      "requiresGraph": "Something went wrong during generation. This could be due to invalid hidden inputs, missing resources, or workflow configuration issues.",
+      "promptVisitGraph": "View the node graph to see the full error.",
+      "getHelp": "For help, view our {0}, {1}, or {2} with the copied error.",
+      "goto": "Show errors in graph",
+      "github": "submit a GitHub issue",
+      "guide": "troubleshooting guide",
+      "support": "contact our support",
+      "promptShow": "Show error report"
+    },
     "queue": {
       "clickToClear": "Click to clear queue",
       "clear": "Clear queue"