refactor: 重构 AgentScope 运行时模块并优化前端附件展示

apps/lib/features/home/ui/screens/home_screen.dart

@@ -470,10 +470,6 @@ class _HomeScreenState extends State<HomeScreen>
                 ),
               ),
             ),
-            if (item.attachments.isNotEmpty && !hasRenderableAttachments) ...[
-              const SizedBox(width: _itemSpacing / 2),
-              _buildAttachmentBadge(item.attachments.length),
-            ],
           ],
         ),
         if (hasRenderableAttachments)
@@ -495,7 +491,7 @@ class _HomeScreenState extends State<HomeScreen>
     final renderableAttachments =
         imageAttachments ?? _collectRenderableImageAttachments(attachments);
     if (renderableAttachments.isEmpty) {
-      return _buildAttachmentBadge(attachments.length);
+      return const SizedBox.shrink();
     }
     return Wrap(
       spacing: _attachmentPreviewGap,
@@ -512,18 +508,18 @@ class _HomeScreenState extends State<HomeScreen>
   }
 
   bool _isRenderableImageAttachment(Map<String, dynamic> attachment) {
+    final url = attachment['url'];
     final mimeType = attachment['mimeType'];
-    final previewPath = attachment['previewPath'];
-    return mimeType is String &&
-        mimeType.startsWith('image/') &&
-        previewPath is String &&
-        previewPath.isNotEmpty;
+    return url is String &&
+        url.isNotEmpty &&
+        mimeType is String &&
+        mimeType.startsWith('image/');
   }
 
   Widget _buildHistoryAttachmentTile(Map<String, dynamic> attachment) {
-    final previewPath = attachment['previewPath'];
-    if (previewPath is! String || previewPath.isEmpty) {
-      return _buildAttachmentBadge(1);
+    final url = attachment['url'];
+    if (url is! String || url.isEmpty) {
+      return const SizedBox.shrink();
     }
     return ClipRRect(
       borderRadius: BorderRadius.circular(_attachmentPreviewRadius),
@@ -531,51 +527,35 @@ class _HomeScreenState extends State<HomeScreen>
         width: _attachmentPreviewSize,
         height: _attachmentPreviewSize,
         color: AppColors.slate100,
-        child: FutureBuilder<Uint8List?>(
-          future: _chatBloc.loadAttachmentPreview(previewPath),
-          builder: (context, snapshot) {
-            if (snapshot.connectionState == ConnectionState.waiting) {
-              return const Center(
-                child: SizedBox(
-                  width: _transcribingSpinnerSize,
-                  height: _transcribingSpinnerSize,
-                  child: CircularProgressIndicator(
-                    strokeWidth: _transcribingStrokeWidth,
-                  ),
+        child: Image.network(
+          url,
+          fit: BoxFit.cover,
+          loadingBuilder: (context, child, loadingProgress) {
+            if (loadingProgress == null) return child;
+            return const Center(
+              child: SizedBox(
+                width: _transcribingSpinnerSize,
+                height: _transcribingSpinnerSize,
+                child: CircularProgressIndicator(
+                  strokeWidth: _transcribingStrokeWidth,
                 ),
-              );
-            }
-            final data = snapshot.data;
-            if (data == null || data.isEmpty) {
-              return const Center(
-                child: Icon(
-                  LucideIcons.imageOff,
-                  size: _iconSize,
-                  color: AppColors.slate500,
-                ),
-              );
-            }
-            return Image.memory(data, fit: BoxFit.cover, gaplessPlayback: true);
+              ),
+            );
+          },
+          errorBuilder: (context, error, stackTrace) {
+            return const Center(
+              child: Icon(
+                LucideIcons.imageOff,
+                size: _iconSize,
+                color: AppColors.slate500,
+              ),
+            );
           },
         ),
       ),
     );
   }
 
-  Widget _buildAttachmentBadge(int count) {
-    return Container(
-      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
-      decoration: BoxDecoration(
-        color: AppColors.slate200,
-        borderRadius: BorderRadius.circular(8),
-      ),
-      child: Text(
-        '图片附件 x$count',
-        style: const TextStyle(fontSize: 12, color: AppColors.slate600),
-      ),
-    );
-  }
-
   Widget _buildToolCallItem(ToolCallItem item) {
     final (statusText, statusColor, statusIcon) = switch (item.status) {
       ToolCallStatus.pending => (