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/data/services/api/api_client.dart

@@ -95,8 +95,9 @@ class ApiClient {
       if (response.statusCode == 200) {
         final stringData = await response.transform(utf8.decoder).join();
         final json = jsonDecode(stringData) as List<dynamic>;
-        final activities =
-            json.map((element) => Activity.fromJson(element)).toList();
+        final activities = json
+            .map((element) => Activity.fromJson(element))
+            .toList();
         return Result.ok(activities);
       } else {
         return const Result.error(HttpException("Invalid response"));
@@ -117,8 +118,9 @@ class ApiClient {
       if (response.statusCode == 200) {
         final stringData = await response.transform(utf8.decoder).join();
         final json = jsonDecode(stringData) as List<dynamic>;
-        final bookings =
-            json.map((element) => BookingApiModel.fromJson(element)).toList();
+        final bookings = json
+            .map((element) => BookingApiModel.fromJson(element))
+            .toList();
         return Result.ok(bookings);
       } else {
         return const Result.error(HttpException("Invalid response"));