fix: 修复图片传输 + 记忆开关 + 统一图标

1. fix: 开启工具调用后图片无法传给AI
   - agent-engine.ts: images 为空文字时自动生成分析提示
   - input-area.ts: 图片+文字合并为单条消息，避免历史消息中图片丢失

2. fix: 记忆弹框自动记忆开关点击无响应
   - memory-modal.ts: CSS 类名 memory-toggle → toggle-label，启用完整滑块样式

3. chore: 统一应用图标为科技感羊驼
   - llama.png / llama.ico: 霓虹电路风格羊驼图标

src/renderer/components/input-area.ts

@@ -547,15 +547,19 @@ async function sendMessageWithAgentLoop(text: string, currentSession: ChatSessio
   const images = pendingImages.map(img => img.base64);
 
   if (pendingImages.length > 0) {
-    msgsToAdd.push({
+    const imgDesc = pendingImages.length === 1 ? `[上传了图片: ${pendingImages[0].name}]` : `[上传了 ${pendingImages.length} 张图片]`;
+    const msg: ChatMessage = {
       role: 'user',
-      content: pendingImages.length === 1 ? `[上传了图片: ${pendingImages[0].name}]` : `[上传了 ${pendingImages.length} 张图片]`,
+      content: text ? `${text}\n\n${imgDesc}` : imgDesc,
       images,
       timestamp: now
-    });
+    };
+    if (userFiles.length > 0) {
+      msg.files = userFiles;
+      msg._fileContents = pendingFiles.map(f => ({ language: f.language, content: f.content }));
     }
-
-  if (text || pendingFiles.length > 0) {
+    msgsToAdd.push(msg);
+  } else if (text || pendingFiles.length > 0) {
     const msg: ChatMessage = {
       role: 'user',
       content: text || '',

src/renderer/components/memory-modal.ts

@@ -28,7 +28,7 @@ export function initMemoryModal(): void {
       <div class="modal-header">
         <h3>🧠 Agent 记忆</h3>
         <div style="display:flex;align-items:center;gap:8px;">
-          <label class="memory-toggle" title="自动记忆">
+          <label class="toggle-label" title="自动记忆">
             <input type="checkbox" id="memoryModalToggle" checked>
             <span class="toggle-slider"></span>
           </label>

src/renderer/services/agent-engine.ts

@@ -102,8 +102,11 @@ export async function runAgentLoop(
     });
   }
 
-  const userMsg: OllamaMessage = { role: 'user', content: userContent };
-  if (images?.length) userMsg.images = images;
+  const userMsg: OllamaMessage = {
+    role: 'user',
+    content: userContent || (images?.length ? (images.length > 1 ? `请分析这 ${images.length} 张图片` : '请分析这张图片') : ''),
+    ...(images?.length && { images })
+  };
   messages.push(userMsg);
 
   const tools = getEnabledToolDefinitions();