feat(android): Add screenshot processing for Android assistant

lib/core/utils/android_assistant_handler.dart

@@ -1,5 +1,14 @@
+import 'dart:io';
 import 'package:flutter/services.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:path/path.dart' as path;
+import '../../features/chat/providers/chat_providers.dart';
+import '../../features/chat/services/file_attachment_service.dart';
+import '../services/navigation_service.dart';
+import '../../shared/services/tasks/task_queue.dart';
+import '../providers/app_providers.dart';
+import '../../features/auth/providers/unified_auth_providers.dart';
+import 'debug_logger.dart';
 
 final androidAssistantProvider = Provider(
   (ref) => AndroidAssistantHandler(ref),
@@ -30,6 +39,67 @@ class AndroidAssistantHandler {
     if (call.method == 'analyzeScreen') {
       final String context = call.arguments as String;
       _ref.read(screenContextProvider.notifier).setContext(context);
+    } else if (call.method == 'analyzeScreenshot') {
+      final String screenshotPath = call.arguments as String;
+      await _processScreenshot(screenshotPath);
+    }
+  }
+
+  Future<void> _processScreenshot(String screenshotPath) async {
+    try {
+      DebugLogger.log('Processing screenshot: $screenshotPath', scope: 'assistant');
+
+      // Wait for app to be ready (authenticated and model available)
+      final navState = _ref.read(authNavigationStateProvider);
+      final model = _ref.read(selectedModelProvider);
+
+      if (navState != AuthNavigationState.authenticated || model == null) {
+        DebugLogger.log('App not ready for screenshot processing', scope: 'assistant');
+        return;
+      }
+
+      // Navigate to chat if not already there
+      final isOnChatRoute = NavigationService.currentRoute == Routes.chat;
+      if (!isOnChatRoute) {
+        // Navigation will happen via auth state
+        return;
+      }
+
+      // Start a fresh chat context
+      startNewChat(_ref);
+
+      // Add screenshot as attachment
+      final file = File(screenshotPath);
+      if (!await file.exists()) {
+        DebugLogger.log('Screenshot file not found: $screenshotPath', scope: 'assistant');
+        return;
+      }
+
+      final svc = _ref.read(fileAttachmentServiceProvider);
+      if (svc != null) {
+        final attachment = LocalAttachment(
+          file: file,
+          displayName: path.basename(screenshotPath),
+        );
+
+        _ref.read(attachedFilesProvider.notifier).addFiles([attachment]);
+
+        // Enqueue upload via task queue
+        final activeConv = _ref.read(activeConversationProvider);
+        try {
+          await _ref.read(taskQueueProvider.notifier).enqueueUploadMedia(
+                conversationId: activeConv?.id,
+                filePath: attachment.file.path,
+                fileName: attachment.displayName,
+                fileSize: await attachment.file.length(),
+              );
+          DebugLogger.log('Screenshot uploaded successfully', scope: 'assistant');
+        } catch (e) {
+          DebugLogger.log('Failed to upload screenshot: $e', scope: 'assistant');
+        }
+      }
+    } catch (e) {
+      DebugLogger.log('Failed to process screenshot: $e', scope: 'assistant');
     }
   }
 }