feat(#393): add Share action to App-log screen (shared export helper)

Extract the BLE screen's on-disk log export into lib/utils/log_export.dart and
reuse it on the App-log screen, so both log screens have one consistent Share
action: OS share sheet on mobile, open logs folder on desktop. The shared file
already holds the app log and BLE frames combined.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

lib/screens/app_debug_log_screen.dart

@@ -6,6 +6,7 @@ import '../l10n/l10n.dart';
 import '../services/app_debug_log_service.dart';
 import '../widgets/adaptive_app_bar_title.dart';
 import '../helpers/snack_bar_builder.dart';
+import '../utils/log_export.dart';
 
 class AppDebugLogScreen extends StatelessWidget {
   const AppDebugLogScreen({super.key});
@@ -22,6 +23,11 @@ class AppDebugLogScreen extends StatelessWidget {
             title: AdaptiveAppBarTitle(context.l10n.debugLog_appTitle),
             centerTitle: true,
             actions: [
+              IconButton(
+                tooltip: LogExport.tooltip,
+                icon: Icon(LogExport.icon),
+                onPressed: () => LogExport.shareLogs(context),
+              ),
               IconButton(
                 tooltip: context.l10n.debugLog_copyLog,
                 icon: const Icon(Icons.copy),

lib/screens/ble_debug_log_screen.dart

@@ -1,5 +1,4 @@
 import 'package:flutter/material.dart';
-import 'package:flutter/foundation.dart';
 import 'package:provider/provider.dart';
 import 'package:flutter/services.dart';
 import '../l10n/l10n.dart';
@@ -7,9 +6,7 @@ import '../services/ble_debug_log_service.dart';
 import '../connector/meshcore_protocol.dart';
 import '../widgets/adaptive_app_bar_title.dart';
 import '../helpers/snack_bar_builder.dart';
-import 'package:share_plus/share_plus.dart';
-import 'package:url_launcher/url_launcher.dart';
-import '../services/file_log_service.dart';
+import '../utils/log_export.dart';
 
 enum _BleLogView { frames, rawLogRx }
 
@@ -33,26 +30,14 @@ class _BleDebugLogScreenState extends State<BleDebugLogScreen> {
         final hasEntries = showingFrames
             ? entries.isNotEmpty
             : rawEntries.isNotEmpty;
-        final isMobile =
-            defaultTargetPlatform == TargetPlatform.android ||
-            defaultTargetPlatform == TargetPlatform.iOS;
         return Scaffold(
           appBar: AppBar(
             title: AdaptiveAppBarTitle(context.l10n.debugLog_bleTitle),
             actions: [
               IconButton(
-                tooltip: isMobile ? 'Share logs' : 'Open logs folder',
-                // Platform-standard share glyph: Android uses Icons.share
-                // (connected nodes), iOS uses Icons.ios_share (square+arrow),
-                // desktop reveals the saved file (folder). #396
-                icon: Icon(
-                  defaultTargetPlatform == TargetPlatform.android
-                      ? Icons.share
-                      : isMobile
-                      ? Icons.ios_share
-                      : Icons.folder_open,
-                ),
-                onPressed: () => _exportLogs(context),
+                tooltip: LogExport.tooltip,
+                icon: Icon(LogExport.icon),
+                onPressed: () => LogExport.shareLogs(context),
               ),
               IconButton(
                 tooltip: context.l10n.debugLog_copyLog,
@@ -181,36 +166,6 @@ class _BleDebugLogScreenState extends State<BleDebugLogScreen> {
     );
   }
 
-  /// Export the on-disk log (#97): the system share sheet on mobile, or open the
-  /// logs folder in the file manager on desktop. The file holds both the app log
-  /// and BLE frames, flushed first so it's current.
-  Future<void> _exportLogs(BuildContext context) async {
-    final messenger = ScaffoldMessenger.of(context);
-    final file = await FileLogService.instance.flushAndGetActiveFile();
-    if (file == null) {
-      messenger.showSnackBar(
-        const SnackBar(
-          content: Text('File logging is unavailable on this platform'),
-        ),
-      );
-      return;
-    }
-    final isMobile =
-        defaultTargetPlatform == TargetPlatform.android ||
-        defaultTargetPlatform == TargetPlatform.iOS;
-    if (isMobile) {
-      await SharePlus.instance.share(
-        ShareParams(
-          subject: 'Offband Meshcore logs',
-          files: [XFile(file.path)],
-        ),
-      );
-    } else {
-      final dir = FileLogService.instance.logDir;
-      if (dir != null) await launchUrl(Uri.file(dir.path));
-    }
-  }
-
   void _showRawDialog(BuildContext context, _RawPacketInfo info) {
     showDialog(
       context: context,

lib/utils/log_export.dart

@@ -0,0 +1,56 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:share_plus/share_plus.dart';
+import 'package:url_launcher/url_launcher.dart';
+
+import '../services/file_log_service.dart';
+
+/// Shared log export for the App-log and BLE-log screens (#393, #97).
+///
+/// The on-disk log file ([FileLogService]) holds both the app log and BLE
+/// frames as one combined stream, so either screen exports the same complete
+/// file. Both screens use these helpers so their Share action can't drift.
+class LogExport {
+  const LogExport._();
+
+  static bool get _isMobile =>
+      defaultTargetPlatform == TargetPlatform.android ||
+      defaultTargetPlatform == TargetPlatform.iOS;
+
+  /// Platform-standard glyph: Android share (connected nodes), iOS square+arrow,
+  /// desktop reveals the saved file (folder). #396
+  static IconData get icon => defaultTargetPlatform == TargetPlatform.android
+      ? Icons.share
+      : _isMobile
+      ? Icons.ios_share
+      : Icons.folder_open;
+
+  static String get tooltip => _isMobile ? 'Share logs' : 'Open logs folder';
+
+  /// Flush the on-disk log and hand it to the OS share sheet (mobile), or open
+  /// the logs folder in the file manager (desktop). Shows a snackbar if file
+  /// logging is unavailable (e.g. web).
+  static Future<void> shareLogs(BuildContext context) async {
+    final messenger = ScaffoldMessenger.of(context);
+    final file = await FileLogService.instance.flushAndGetActiveFile();
+    if (file == null) {
+      messenger.showSnackBar(
+        const SnackBar(
+          content: Text('File logging is unavailable on this platform'),
+        ),
+      );
+      return;
+    }
+    if (_isMobile) {
+      await SharePlus.instance.share(
+        ShareParams(
+          subject: 'Offband Meshcore logs',
+          files: [XFile(file.path)],
+        ),
+      );
+    } else {
+      final dir = FileLogService.instance.logDir;
+      if (dir != null) await launchUrl(Uri.file(dir.path));
+    }
+  }
+}