fix: show git hash as clickable link above stacktrace on crash screen (#201)

Previous PRs (#150, #179) added partial implementations that left duplicate
code via a rebase conflict: plain (non-linked) text above the stacktrace and a
clickable link section below it. This consolidates both into a single clickable
link above the stacktrace.

Also makes `gitHash` an injectable constructor parameter so tests can exercise
the link without needing a release build.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/ui/screens/crash_screen.dart

@@ -10,12 +10,12 @@ class CrashScreen extends StatelessWidget {
     super.key,
     required this.exception,
     required this.stackTrace,
+    this.gitHash = const String.fromEnvironment('GIT_HASH'),
   });
 
   final Object exception;
   final StackTrace? stackTrace;
-
-  static const _gitHash = String.fromEnvironment('GIT_HASH');
+  final String gitHash;
 
   Future<String> _buildReport() async {
     String version = 'unknown';
@@ -25,8 +25,8 @@ class CrashScreen extends StatelessWidget {
     } catch (_) {}
     final platform =
         '${Platform.operatingSystem} ${Platform.operatingSystemVersion}';
-    final gitLine = _gitHash.isNotEmpty
-        ? 'Git Commit: [$_gitHash](https://codeberg.org/guettli/sharedinbox/commit/$_gitHash)\n'
+    final gitLine = gitHash.isNotEmpty
+        ? 'Git Commit: [$gitHash](https://codeberg.org/guettli/sharedinbox/commit/$gitHash)\n'
         : '';
     return 'App Version: $version\n'
         '$gitLine'
@@ -56,12 +56,27 @@ class CrashScreen extends StatelessWidget {
                   style: Theme.of(ctx).textTheme.titleMedium,
                   textAlign: TextAlign.center,
                 ),
-                if (_gitHash.isNotEmpty) ...[
+                if (gitHash.isNotEmpty) ...[
                   const SizedBox(height: 8),
-                  const Text(
-                    'Git Commit: $_gitHash',
-                    style: TextStyle(fontSize: 12, color: Colors.grey),
-                    textAlign: TextAlign.center,
+                  GestureDetector(
+                    onTap: () async {
+                      final url = Uri.parse(
+                        'https://codeberg.org/guettli/sharedinbox/commit/$gitHash',
+                      );
+                      await launchUrl(
+                        url,
+                        mode: LaunchMode.externalApplication,
+                      );
+                    },
+                    child: Text(
+                      'Git Commit: $gitHash',
+                      style: const TextStyle(
+                        fontSize: 12,
+                        color: Colors.blue,
+                        decoration: TextDecoration.underline,
+                      ),
+                      textAlign: TextAlign.center,
+                    ),
                   ),
                 ],
                 const SizedBox(height: 24),
@@ -106,32 +121,6 @@ class CrashScreen extends StatelessWidget {
                     ),
                   ),
                 ],
-                if (_gitHash.isNotEmpty) ...[
-                  const SizedBox(height: 16),
-                  const Text(
-                    'Git Commit:',
-                    style: TextStyle(fontWeight: FontWeight.bold),
-                  ),
-                  const SizedBox(height: 4),
-                  GestureDetector(
-                    onTap: () async {
-                      final url = Uri.parse(
-                        'https://codeberg.org/guettli/sharedinbox/commit/$_gitHash',
-                      );
-                      await launchUrl(
-                        url,
-                        mode: LaunchMode.externalApplication,
-                      );
-                    },
-                    child: const Text(
-                      _gitHash,
-                      style: TextStyle(
-                        color: Colors.blue,
-                        decoration: TextDecoration.underline,
-                      ),
-                    ),
-                  ),
-                ],
                 const SizedBox(height: 24),
                 FilledButton.icon(
                   onPressed: () async {

test/widget/crash_screen_test.dart

@@ -123,6 +123,50 @@ void main() {
     },
   );
 
+  testWidgets(
+    'CrashScreen shows git hash as clickable link above stacktrace',
+    (tester) async {
+      tester.view.physicalSize = const Size(800, 1200);
+      tester.view.devicePixelRatio = 1.0;
+      addTearDown(() => tester.view.resetPhysicalSize());
+
+      final mock = MockUrlLauncher();
+      UrlLauncherPlatform.instance = mock;
+
+      const exception = 'TestException: git hash test';
+      final stackTrace = StackTrace.current;
+      const testHash = 'abc1234';
+
+      await tester.pumpWidget(
+        CrashScreen(
+          exception: exception,
+          stackTrace: stackTrace,
+          gitHash: testHash,
+        ),
+      );
+
+      // Git hash link should be present
+      final gitLinkFinder = find.textContaining('Git Commit: abc1234');
+      expect(gitLinkFinder, findsOneWidget);
+
+      // Link must appear above the stack trace
+      final stackTraceFinder = find.text('Stack Trace:');
+      expect(
+        tester.getTopLeft(gitLinkFinder).dy,
+        lessThan(tester.getTopLeft(stackTraceFinder).dy),
+      );
+
+      // Tapping the link should open the Codeberg commit URL
+      await tester.tap(gitLinkFinder);
+      await tester.pumpAndSettle();
+
+      expect(
+        mock.launchedUrl,
+        equals('https://codeberg.org/guettli/sharedinbox/commit/abc1234'),
+      );
+    },
+  );
+
   testWidgets(
     'CrashScreen used as root widget — buttons work without ScaffoldMessenger crash',
     (tester) async {