Show full Dart SDK version for beta releases in the archive (#12604)

Includes the full Dart SDK build in the Flutter SDK archive table for
beta releases.

Resolves #12580

**Staged:**
https://flutter-docs-prod--pr12604-fix-12580-mhna4o14.web.app/install/archive#beta-channel

Co-authored-by: Shams Zakhour <[email protected]>

Author: parlough

site/lib/src/components/pages/archive_table.dart

@@ -86,7 +86,7 @@ class _ArchiveTableState extends State<ArchiveTable> {
                 th([text('Flutter version')]),
                 th([text('Architecture')]),
                 th([text('Ref')]),
-                th(classes: 'date', [text('Release Date')]),
+                th(classes: 'date', [text('Release date')]),
                 th([text('Dart version')]),
                 th([text('Provenance')]),
               ]),

site/lib/src/models/flutter_release_model.dart

@@ -9,6 +9,8 @@ import 'package:universal_web/js_interop.dart';
 
 /// Represents a Flutter release loaded from the Flutter releases endpoint.
 class FlutterRelease {
+  static final RegExp _dartSdkBuildPattern = RegExp(r'\(build\s(.*?)\)');
+
   FlutterRelease({
     required this.url,
     required this.version,
@@ -20,12 +22,18 @@ class FlutterRelease {
   });
 
   factory FlutterRelease.fromJson(Map<String, Object?> json, String baseUrl) {
+    final dartSdkVersion = switch (json['dart_sdk_version']) {
+      final String rawDartSdkVersion when rawDartSdkVersion.isNotEmpty =>
+        _dartSdkBuildPattern.firstMatch(rawDartSdkVersion)?.group(1) ??
+            rawDartSdkVersion.trim(),
+      _ => '-',
+    };
+
     return FlutterRelease(
       url: '$baseUrl/${json['archive'] as String}',
       version: json['version'] as String,
       channel: json['channel'] as String,
-      dartSdkVersion:
-          (json['dart_sdk_version'] as String?)?.split(' ')[0] ?? '-',
+      dartSdkVersion: dartSdkVersion,
       architecture: (json['dart_sdk_arch'] as String?) ?? 'x64',
       hash: (json['hash'] as String).substring(0, 7),
       releaseDate: Date(Date.parse(json['release_date'] as String)),

site/lib/src/style_hash.dart

@@ -2,4 +2,4 @@
 // dart format off
 
 /// The generated hash of the `main.css` file.
-const generatedStylesHash = 'ugxj95DjrnBJ';
+const generatedStylesHash = 'nvTevrLjFn98';