feat: 功能1 - 新建机器人 (v0.9.6)

- 添加 CreateBotModal.vue 新建机器人模态框
- 实现12个预设头像选择
- 实现名称/显示名称/描述表单
- HomeView 添加「新建机器人」按钮
- Store 添加 createBot 方法
- Store 添加 fetchAgents 方法
- 表单验证和错误提示

frontend/src/views/HomeView.vue

@@ -1,13 +1,16 @@
 <script setup lang="ts">
-import { onMounted } from 'vue'
+import { ref, onMounted } from 'vue'
 import { useRouter } from 'vue-router'
 import { useAuthStore } from '@/stores/auth'
 import { useChatStore } from '@/stores/chat'
+import CreateBotModal from '@/components/chat/CreateBotModal.vue'
 
 const router = useRouter()
 const authStore = useAuthStore()
 const chatStore = useChatStore()
 
+const showCreateBot = ref(false)
+
 onMounted(async () => {
   await chatStore.fetchBots()
   await chatStore.fetchSessions()
@@ -24,6 +27,10 @@ function startChat(botId: string) {
 function resumeChat(sessionId: string) {
   router.push({ name: 'chat', params: { sessionId } })
 }
+
+function handleBotCreated(bot: any) {
+  chatStore.bots.push(bot)
+}
 </script>
 
 <template>
@@ -31,9 +38,14 @@ function resumeChat(sessionId: string) {
     <header class="header">
       <div class="header-content">
         <h1>🐕 智队中枢</h1>
-        <div class="user-info">
-          <span>{{ authStore.user?.nickname || authStore.user?.username }}</span>
-          <button class="logout-btn" @click="authStore.logout">退出</button>
+        <div class="user-actions">
+          <button class="new-bot-btn" @click="showCreateBot = true">
+            + 新建机器人
+          </button>
+          <div class="user-info">
+            <span>{{ authStore.user?.nickname || authStore.user?.username }}</span>
+            <button class="logout-btn" @click="authStore.logout">退出</button>
+          </div>
         </div>
       </div>
     </header>
@@ -92,6 +104,12 @@ function resumeChat(sessionId: string) {
         </div>
       </section>
     </main>
+
+    <CreateBotModal
+      v-if="showCreateBot"
+      @close="showCreateBot = false"
+      @created="handleBotCreated"
+    />
   </div>
 </template>
 
@@ -120,6 +138,28 @@ function resumeChat(sessionId: string) {
   color: var(--primary-color);
 }
 
+.user-actions {
+  display: flex;
+  align-items: center;
+  gap: var(--spacing-md);
+}
+
+.new-bot-btn {
+  padding: var(--spacing-xs) var(--spacing-md);
+  background: var(--primary-color);
+  color: white;
+  border: none;
+  border-radius: var(--border-radius);
+  font-size: var(--font-size-sm);
+  font-weight: 500;
+  cursor: pointer;
+  transition: background 0.2s;
+}
+
+.new-bot-btn:hover {
+  background: var(--primary-dark);
+}
+
 .user-info {
   display: flex;
   align-items: center;