智能体大模型接口全面切换 + 新增视觉智能体

- 全部 AI Worker 切换到 deepseek/deepseek-v4-flash（api.deepseek.com，实测757ms/次，成本降40倍）
- 团队模板默认 provider/model 同步改为 deepseek/deepseek-v4-flash
- 新增视觉智能体「视觉分析师」：autodl/qwen3.6-plus 多模态
- llm_gateway: chat_vision 多模态调用(URL/base64) + 空content自动重试 + 聚合后端路由容错
- engine: 任务描述支持 ![图](url) 图片注入（视觉任务直接派活）
- API: POST /api/workers/<id>/vision_test；前端 Worker 页新增🖼️视觉测试按钮
- 实测: 截图结构化分析 ✅ 雪羊图片识别 ✅ 辩论模式DeepSeek 55秒完成

llm_gateway.py

@@ -30,7 +30,12 @@ def calc_cost(model, prompt_tokens, completion_tokens):
 
 def chat(provider, model, messages, temperature=0.7, max_tokens=None,
          base_url=None, api_key=None, timeout=None, retries=None):
-    """调用 OpenAI 兼容 chat/completions，返回 {text, usage, cost, model}"""
+    """调用 OpenAI 兼容 chat/completions，返回 {text, usage, cost, model}
+    messages 支持两种格式：
+      - 纯文本：[{'role':'user','content':'...'}]
+      - 多模态：[{'role':'user','content':[{'type':'text','text':'...'},
+                                        {'type':'image_url','image_url':{'url':'...'}}]}]
+    """
     cfg = get_provider_cfg(provider)
     url = (base_url or cfg['base_url']).rstrip('/') + '/chat/completions'
     key = api_key or cfg['api_key']
@@ -56,7 +61,14 @@ def chat(provider, model, messages, temperature=0.7, max_tokens=None,
             resp = requests.post(url, json=payload, headers=headers, timeout=timeout)
             if resp.status_code == 200:
                 data = resp.json()
-                text = data['choices'][0]['message']['content'] or ''
+                msg = data['choices'][0]['message']
+                text = msg.get('content') or ''
+                if not text:
+                    # 推理模型偶发 content 为空：用 reasoning_content 兜底
+                    text = msg.get('reasoning_content') or ''
+                if not text:
+                    last_err = LLMError('模型返回空内容，重试中…')
+                    continue
                 usage = data.get('usage', {})
                 pt = usage.get('prompt_tokens', 0)
                 ct = usage.get('completion_tokens', 0)
@@ -84,6 +96,48 @@ def chat(provider, model, messages, temperature=0.7, max_tokens=None,
     raise last_err or LLMError('未知错误')
 
 
+def chat_vision(provider, model, text, image_url=None, image_path=None,
+                temperature=0.4, max_tokens=2000, base_url=None, api_key=None,
+                retries=3):
+    """多模态视觉调用：文本 + 图片（URL 或本地路径/base64）。
+    返回与 chat() 相同结构。
+    容错：聚合 API 偶发路由到纯文本后端（不认识 image_url），自动重试。"""
+    import base64 as _b64
+    import time as _time
+    content = [{'type': 'text', 'text': text}]
+    img_url = image_url
+    if image_path:
+        with open(image_path, 'rb') as f:
+            raw = f.read()
+        mime = 'image/png'
+        if image_path.lower().endswith(('.jpg', '.jpeg')):
+            mime = 'image/jpeg'
+        elif image_path.lower().endswith('.gif'):
+            mime = 'image/gif'
+        elif image_path.lower().endswith('.webp'):
+            mime = 'image/webp'
+        img_url = f'data:{mime};base64,{_b64.b64encode(raw).decode()}'
+    if img_url:
+        content.append({'type': 'image_url', 'image_url': {'url': img_url}})
+    messages = [{'role': 'user', 'content': content}]
+    last_err = None
+    for attempt in range(max(1, retries)):
+        try:
+            return chat(provider, model, messages,
+                        temperature=temperature, max_tokens=max_tokens,
+                        base_url=base_url, api_key=api_key)
+        except LLMError as e:
+            last_err = e
+            msg = str(e)
+            # 仅对“多模态格式不被支持/图片无效”类错误重试（聚合后端路由问题）
+            if any(k in msg for k in ('image_url', 'InvalidParameter', 'invalid_parameter',
+                                      'does not appear to be valid', 'image')):
+                _time.sleep(2 * (attempt + 1))
+                continue
+            raise
+    raise last_err or LLMError('视觉调用失败')
+
+
 def test_connection(provider, model, base_url=None, api_key=None):
     """连通性测试：发一条最小请求"""
     t0 = time.time()