新增：AI 接口连通性测试功能；修复：Ollama 超时问题

- 后台 AI 厂商列表新增「⚡ 测试」按钮，实时验证接口连通性
- 显示响应耗时（含冷启动）和模型返回内容
- AiChatService 请求超时从 30s 调整为 120s（兼容 Ollama 本地冷启动）
- 测试接口超时设为 60s

app/Http/Controllers/Admin/AiProviderController.php

@@ -200,6 +200,67 @@ class AiProviderController extends Controller
         ]);
     }
 
+    /**
+     * 测试指定 AI 厂商的接口连通性
+     *
+     * 发送一条简短的测试消息，返回响应结果和耗时，用于验证配置是否正确。
+     *
+     * @param  int  $id  厂商配置 ID
+     * @return JsonResponse 测试结果
+     */
+    public function testConnection(int $id): JsonResponse
+    {
+        $provider = AiProviderConfig::findOrFail($id);
+
+        $apiKey = $provider->getDecryptedApiKey();
+        $base = rtrim($provider->api_endpoint, '/');
+        $endpoint = str_ends_with($base, '/v1')
+            ? $base.'/chat/completions'
+            : $base.'/v1/chat/completions';
+
+        $startTime = microtime(true);
+
+        try {
+            $response = \Illuminate\Support\Facades\Http::withToken($apiKey)
+                ->timeout(60)  // Ollama 本地模型冷启动较慢，给 60s
+                ->post($endpoint, [
+                    'model' => $provider->model,
+                    'messages' => [
+                        ['role' => 'user', 'content' => '请用一句话介绍你自己。'],
+                    ],
+                    'max_tokens' => 64,
+                ]);
+
+            $ms = (int) ((microtime(true) - $startTime) * 1000);
+            $data = $response->json();
+
+            if (! $response->successful()) {
+                return response()->json([
+                    'ok' => false,
+                    'message' => "HTTP {$response->status()}：{$response->body()}",
+                    'ms' => $ms,
+                ]);
+            }
+
+            $reply = $data['choices'][0]['message']['content'] ?? '（无回复内容）';
+
+            return response()->json([
+                'ok' => true,
+                'message' => trim($reply),
+                'ms' => $ms,
+                'model' => $data['model'] ?? $provider->model,
+            ]);
+        } catch (\Illuminate\Http\Client\ConnectionException $e) {
+            $ms = (int) ((microtime(true) - $startTime) * 1000);
+
+            return response()->json([
+                'ok' => false,
+                'message' => '连接失败：'.$e->getMessage(),
+                'ms' => $ms,
+            ]);
+        }
+    }
+
     /**
      * 删除 AI 厂商配置
      *