feat(config): 添加模型助手功能以选择和管理模型

本次提交主要包含以下更改：

1. **后端更新**:
   - 在 `app/service/config/config_service.py` 中新增 `fetch_ui_models` 方法，用于获取可用于 UI 的模型列表，并处理相关的错误情况。
   - 在 `app/router/config_routes.py` 中新增 `/ui/models` 路由，提供模型列表的 API 接口，并添加身份验证逻辑。

2. **前端更新**:
   - 在 `app/static/js/config_editor.js` 中实现模型助手的功能，包括模型列表的加载、搜索和选择。
   - 在 `app/templates/config_editor.html` 中添加模型助手的模态框和相关的 UI 元素，允许用户从列表中选择模型。

这些更改旨在增强用户体验，使用户能够更方便地选择和管理模型，提高配置界面的交互性和功能性。

app/templates/config_editor.html

@@ -557,13 +557,23 @@ endblock %} {% block head_extra_styles %}
           <label for="TEST_MODEL" class="block font-semibold mb-2 text-gray-700"
             >测试模型</label
           >
-          <input
-            type="text"
-            id="TEST_MODEL"
-            name="TEST_MODEL"
-            placeholder="gemini-1.5-flash"
-            class="w-full px-4 py-3 rounded-lg border border-gray-300 focus:border-primary-500 focus:ring focus:ring-primary-200 focus:ring-opacity-50 form-input-themed"
-          />
+          <div class="flex items-center gap-2">
+            <input
+              type="text"
+              id="TEST_MODEL"
+              name="TEST_MODEL"
+              placeholder="gemini-1.5-flash"
+              class="flex-grow px-4 py-3 rounded-lg border border-gray-300 focus:border-primary-500 focus:ring focus:ring-primary-200 focus:ring-opacity-50 form-input-themed"
+            />
+            <button
+              type="button"
+              title="选择模型"
+              class="model-helper-trigger-btn p-2 rounded-md text-violet-300 hover:bg-violet-700 transition-colors"
+              data-target-input-id="TEST_MODEL"
+            >
+              <i class="fas fa-list-ul"></i>
+            </button>
+          </div>
           <small class="text-gray-500 mt-1 block">用于测试API密钥的模型</small>
         </div>
 
@@ -577,7 +587,15 @@ endblock %} {% block head_extra_styles %}
           <div class="array-container" id="IMAGE_MODELS_container">
             <!-- 数组项将在这里动态添加 -->
           </div>
-          <div class="flex justify-end">
+          <div class="flex justify-end gap-2 mt-2">
+            <button
+              type="button"
+              title="从列表选择模型添加到下方"
+              class="model-helper-trigger-btn p-2 rounded-md text-violet-300 hover:bg-violet-700 transition-colors"
+              data-target-array-key="IMAGE_MODELS"
+            >
+              <i class="fas fa-list-ul"></i>
+            </button>
             <button
               type="button"
               class="bg-violet-600 hover:bg-violet-700 text-white px-4 py-2 rounded-lg font-medium transition-all duration-200 flex items-center gap-2"
@@ -599,7 +617,15 @@ endblock %} {% block head_extra_styles %}
           <div class="array-container" id="SEARCH_MODELS_container">
             <!-- 数组项将在这里动态添加 -->
           </div>
-          <div class="flex justify-end">
+          <div class="flex justify-end gap-2 mt-2">
+            <button
+              type="button"
+              title="从列表选择模型添加到下方"
+              class="model-helper-trigger-btn p-2 rounded-md text-violet-300 hover:bg-violet-700 transition-colors"
+              data-target-array-key="SEARCH_MODELS"
+            >
+              <i class="fas fa-list-ul"></i>
+            </button>
             <button
               type="button"
               class="bg-violet-600 hover:bg-violet-700 text-white px-4 py-2 rounded-lg font-medium transition-all duration-200 flex items-center gap-2"
@@ -621,7 +647,15 @@ endblock %} {% block head_extra_styles %}
           <div class="array-container" id="FILTERED_MODELS_container">
             <!-- 数组项将在这里动态添加 -->
           </div>
-          <div class="flex justify-end">
+          <div class="flex justify-end gap-2 mt-2">
+            <button
+              type="button"
+              title="从列表选择模型添加到下方"
+              class="model-helper-trigger-btn p-2 rounded-md text-violet-300 hover:bg-violet-700 transition-colors"
+              data-target-array-key="FILTERED_MODELS"
+            >
+              <i class="fas fa-list-ul"></i>
+            </button>
             <button
               type="button"
               class="bg-violet-600 hover:bg-violet-700 text-white px-4 py-2 rounded-lg font-medium transition-all duration-200 flex items-center gap-2"
@@ -708,7 +742,15 @@ endblock %} {% block head_extra_styles %}
           <div class="array-container" id="THINKING_MODELS_container">
             <!-- 数组项将在这里动态添加 -->
           </div>
-          <div class="flex justify-end">
+          <div class="flex justify-end gap-2 mt-2">
+            <button
+              type="button"
+              title="从列表选择模型添加到下方"
+              class="model-helper-trigger-btn p-2 rounded-md text-violet-300 hover:bg-violet-700 transition-colors"
+              data-target-array-key="THINKING_MODELS"
+            >
+              <i class="fas fa-list-ul"></i>
+            </button>
             <button
               type="button"
               class="bg-violet-600 hover:bg-violet-700 text-white px-4 py-2 rounded-lg font-medium transition-all duration-200 flex items-center gap-2"
@@ -829,13 +871,23 @@ endblock %} {% block head_extra_styles %}
             class="block font-semibold mb-2 text-gray-700"
             >图像生成模型</label
           >
-          <input
-            type="text"
-            id="CREATE_IMAGE_MODEL"
-            name="CREATE_IMAGE_MODEL"
-            placeholder="imagen-3.0-generate-002"
-            class="w-full px-4 py-3 rounded-lg border border-gray-300 focus:border-primary-500 focus:ring focus:ring-primary-200 focus:ring-opacity-50 form-input-themed"
-          />
+          <div class="flex items-center gap-2">
+            <input
+              type="text"
+              id="CREATE_IMAGE_MODEL"
+              name="CREATE_IMAGE_MODEL"
+              placeholder="imagen-3.0-generate-002"
+              class="flex-grow px-4 py-3 rounded-lg border border-gray-300 focus:border-primary-500 focus:ring focus:ring-primary-200 focus:ring-opacity-50 form-input-themed"
+            />
+            <button
+              type="button"
+              title="选择模型"
+              class="model-helper-trigger-btn p-2 rounded-md text-violet-300 hover:bg-violet-700 transition-colors"
+              data-target-input-id="CREATE_IMAGE_MODEL"
+            >
+              <i class="fas fa-list-ul"></i>
+            </button>
+          </div>
           <small class="text-gray-500 mt-1 block">用于图像生成的模型</small>
         </div>
 
@@ -1505,6 +1557,55 @@ endblock %} {% block head_extra_styles %}
   </div>
 </div>
 
+<!-- Model Helper Modal -->
+<div id="modelHelperModal" class="modal">
+  <div
+    class="w-full max-w-lg mx-auto rounded-2xl shadow-2xl overflow-hidden animate-fade-in"
+    style="
+      background-color: rgba(70, 50, 150, 0.95);
+      color: #ffffff;
+      border: 1px solid rgba(120, 100, 200, 0.4);
+    "
+  >
+    <div class="p-6">
+      <div class="flex justify-between items-center mb-4">
+        <h2 id="modelHelperTitle" class="text-xl font-bold text-gray-100">
+          选择模型
+        </h2>
+        <button
+          id="closeModelHelperModalBtn"
+          class="text-gray-300 hover:text-gray-100 text-xl"
+        >
+          &times;
+        </button>
+      </div>
+      <input
+        type="text"
+        id="modelHelperSearchInput"
+        placeholder="搜索模型..."
+        class="w-full px-4 py-3 mb-4 rounded-lg border font-mono text-sm form-input-themed"
+      />
+      <div
+        id="modelHelperListContainer"
+        class="array-container"
+        style="max-height: 300px; overflow-y: auto"
+      >
+        <!-- Model items will be populated here -->
+        <p class="text-gray-400 text-sm italic">正在加载模型列表...</p>
+      </div>
+      <div class="flex justify-end gap-3 mt-6">
+        <button
+          type="button"
+          id="cancelModelHelperBtn"
+          class="bg-gray-500 bg-opacity-50 hover:bg-opacity-70 text-gray-200 px-6 py-2 rounded-lg font-medium transition"
+        >
+          关闭
+        </button>
+      </div>
+    </div>
+  </div>
+</div>
+
 {% endblock %} {% block body_scripts %}
 <script src="/static/js/config_editor.js"></script>
 <!-- 增强下拉框样式和交互性 -->