feat: Implement push notification suppression for active chats, prevent duplicate self-messages, update the chat typing indicator, and add back buttons to static screens.

lib/features/about/presentation/screens/about_screen.dart

@@ -314,7 +314,36 @@ class AboutScreen extends ConsumerWidget {
       physics: const AlwaysScrollableScrollPhysics(),
       child: Column(
         children: [
-          const SizedBox(height: 18),
+          // Back button
+          Padding(
+            padding: const EdgeInsets.fromLTRB(16, 8, 16, 0),
+            child: Align(
+              alignment: Alignment.centerLeft,
+              child: GestureDetector(
+                onTap: () {
+                  if (Navigator.of(context).canPop()) {
+                    Navigator.of(context).pop();
+                  } else {
+                    context.go('/home');
+                  }
+                },
+                child: Container(
+                  width: 36,
+                  height: 36,
+                  decoration: BoxDecoration(
+                    color: AppColors.primaryDark.withValues(alpha: 0.08),
+                    shape: BoxShape.circle,
+                  ),
+                  child: const Icon(
+                    Icons.arrow_back_ios_new_rounded,
+                    color: AppColors.primaryDark,
+                    size: 18,
+                  ),
+                ),
+              ),
+            ),
+          ),
+          const SizedBox(height: 10),
           _buildHeroTitle(state.hero.headline),
           const SizedBox(height: 16),
           _buildHeroSubtitle(state.hero.description),