docs: remove alpha warning from apps pages except skills & agents (#19919)

## Summary
- Remove the \"Apps are currently in alpha\" warning from 8 pages under
`developers/extend/apps/` (getting-started, architecture/building,
data-model, layout, logic-functions, front-components, cli-and-testing,
publishing).
- Keep the warning on the Skills & Agents page only, and reword it to
scope it to that feature: \"Skills and agents are currently in alpha.
The feature works but is still evolving.\"

## Test plan
- [ ] Preview docs build and confirm the warning banner no longer
appears on the 8 pages above.
- [ ] Confirm the warning still renders on the Skills & Agents page with
the updated wording.

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

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/twenty-docs/developers/extend/apps/cli-and-testing.mdx

@@ -4,10 +4,6 @@ description: CLI commands, testing setup, public assets, npm packages, remotes,
 icon: "terminal"
 ---
 
-<Warning>
-  Apps are currently in alpha. The feature works but is still evolving.
-</Warning>
-
 ## Public assets (`public/` folder)
 
 The `public/` folder at the root of your app holds static files — images, icons, fonts, or any other assets your app needs at runtime. These files are automatically included in builds, synced during dev mode, and uploaded to the server.