Dart 3.9 / Flutter 3.35 [first LLM release] (#2714)

I got carried away with Gemini and basically rewrote CI and the release
process for the new LLM reality. This work was largely completed by
Gemini.

- Bump all SDK versions to the current beta (3.9.0-0)
- Run `flutter channel beta`
- Wrote `ci_script.dart` to replace the bash scripts
- Converted repository to pub workspace #2499 
- Added llm.md and release.md
- Added redirect for deprecated Samples Index

## Pre-launch Checklist

- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I have added sample code updates to the [changelog].
- [x] I updated/added relevant documentation (doc comments with `///`).

compass_app/app/lib/ui/auth/login/widgets/login_screen.dart

@@ -101,11 +101,10 @@ class _LoginScreenState extends State<LoginScreen> {
           content: Text(AppLocalization.of(context).errorWhileLogin),
           action: SnackBarAction(
             label: AppLocalization.of(context).tryAgain,
-            onPressed:
-                () => widget.viewModel.login.execute((
-                  _email.value.text,
-                  _password.value.text,
-                )),
+            onPressed: () => widget.viewModel.login.execute((
+              _email.value.text,
+              _password.value.text,
+            )),
           ),
         ),
       );