## Summary
Adds handling for entering app mode with an empty graph prompting the
user to load a template as a starting point
## Changes
- **What**:
- app mode handle empty workflows, disable builder button, show
different message
- fix fitView when switching from app mode to graph
## Review Focus
Moving the fitView since the canvas is hidden in app mode until after
the workflow is loaded and the mode has been switched back to graph, I
don't see how this could cause any issues but worth a closer eye
## Screenshots (if applicable)
<img width="1057" height="916" alt="image"
src="https://github.com/user-attachments/assets/2ffe2b6d-9ce1-4218-828a-b7bc336c365a"
/>
┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9393-feat-App-mode-empty-graph-handling-3196d73d3650812cab0ce878109ed5c9)
by [Unito](https://www.unito.io)
## Summary
Change app mode changes to be written directly to the workflow on change
instead of requiring explicit save via builder.
Temporary: Adds `.app.json` file extension to app files for
identification since we don't currently have a way to identify them with
metadata
Removes app builder save dialog and replaces it with default mode
selection
## Changes
- **What**:
- ensure all save locations handle app mode
- remove dirtyLinearData and flushing
- **Breaking**:
- if people are relying on workflow names and are converting to/from app
mode in the same workflow, they will gain/lose the `.app` part of the
extension
## Screenshots (if applicable)
<img width="689" height="84" alt="image"
src="https://github.com/user-attachments/assets/335596ee-dce9-4e3a-a7b5-f0715c294e41"
/>
<img width="421" height="324" alt="image"
src="https://github.com/user-attachments/assets/ad3cd33c-e9f0-4c30-8874-d4507892fc6b"
/>
┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9338-feat-App-mode-saving-rework-3176d73d3650813f9ae1f6c5a234da8c)
by [Unito](https://www.unito.io)
