feat(search): 网络搜索新增 DeepSeek 官方来源

不单独配置凭据，直接复用当前激活的 LLM 配置(base_url/api_key/model)。

这个来源与 ddgs/brave/tavily 性质不同：DeepSeek 没有可直接调用的搜索接口，
搜索只存在于其 Anthropic 兼容 messages 接口内部，以 web_search_20250305
服务端工具的形式由 DeepSeek 服务端执行。由此带来几个必须让用户知道的差异，
已在设置页写明：

- 仅支持 DeepSeek 官方端点 + anthropic 协议。实测其 OpenAI 协议端点会直接以
  "unknown variant, expected `function`" 拒绝一切服务端工具，web_search_options
  之类的顶层字段则被静默忽略，没有可用的替代写法。
- 每次搜索额外消耗一次模型调用。
- 搜索请求由 DeepSeek 服务端发出，不经过搜索出口代理，也不计入流量留痕。
- 返回结果只有标题与链接，没有摘要(DeepSeek 只给 encrypted_content)，需要正文
  时仍由 WebFetch 抓取。

上述条件不做程序校验，仅在界面说明，由用户自行确认——配置不满足时搜索会在实际
调用时报错，与其它来源填错 Key 的反馈路径一致，可用「测试搜索」按钮实跑验证。

依赖 norma v0.3.8。

server/manager.go

@@ -273,6 +273,9 @@ const (
 	settingConcurrencyLimit = "task_concurrency_limit"
 	// defaultWebSearchBackend is used when web search is on but no backend was picked.
 	defaultWebSearchBackend = "ddgs"
+	// deepSeekWebSearchBackend borrows the active LLM profile instead of its own
+	// key, so it only works on an anthropic-format profile pointed at DeepSeek.
+	deepSeekWebSearchBackend = "deepseek"
 	// defaultWorkers is the concurrent work-agent count when the setting is unset.
 	defaultWorkers = 3
 	// defaultConcurrencyLimit is the simultaneous-running-task cap when the feature
@@ -539,7 +542,26 @@ func (m *Manager) WebSearchOpts() agent.WebSearchOpts {
 	if on && backend == "tavily" && strings.TrimSpace(tavilyKey) == "" {
 		on = false
 	}
-	return agent.WebSearchOpts{Enabled: on, Backend: backend, BraveKey: braveKey, TavilyKey: tavilyKey, Proxy: proxy}
+	o := agent.WebSearchOpts{Enabled: on, Backend: backend, BraveKey: braveKey, TavilyKey: tavilyKey, Proxy: proxy}
+	if backend == deepSeekWebSearchBackend {
+		o.DeepSeekBaseURL, o.DeepSeekAPIKey, o.DeepSeekModel = m.deepSeekSearchCreds()
+	}
+	return o
+}
+
+// deepSeekSearchCreds resolves the credentials the "deepseek" search backend
+// borrows from the active LLM profile (it has no key of its own). Whether that
+// profile can actually drive server-side search — DeepSeek exposes it only on
+// the Anthropic-format endpoint — is deliberately NOT validated here: the UI
+// states the requirement and the user decides. A profile that can't serve it
+// simply fails at search time (or at the settings page's 测试 button), which is
+// the same feedback every other backend gives for a bad key.
+func (m *Manager) deepSeekSearchCreds() (baseURL, apiKey, model string) {
+	p, err := m.pg.ActiveProfile()
+	if err != nil || p == nil {
+		return "", "", ""
+	}
+	return p.BaseURL, p.APIKey, p.Model
 }
 
 // SetWebSearch persists and applies the web-search settings. braveKey, tavilyKey, and

server/server.go

@@ -3413,10 +3413,22 @@ func (s *Server) testWebSearch(w http.ResponseWriter, r *http.Request) {
 	if strings.TrimSpace(req.TavilyKey) != "" {
 		tavilyKey = req.TavilyKey
 	}
+	cfg := actool.WebSearchConfig{Backend: backend, BraveAPIKey: braveKey, TavilyAPIKey: tavilyKey, Proxy: proxy}
 	// Hard cap so a slow/blocked proxy can't hang the request.
-	ctx, cancel := context.WithTimeout(r.Context(), 30*time.Second)
+	wall := 30 * time.Second
+	// deepseek 的凭据不在表单里，来自当前激活的 LLM 配置；同时它每次搜索都跑一次
+	// 模型推理，30s 的通用上限偏紧，单独放宽。这里不预判配置能不能用——测这一下
+	// 本来就是给用户自己确认的手段，真跑不通时下面的报错比预判更有信息量。
+	probeQuery := "test"
+	if strings.TrimSpace(backend) == deepSeekWebSearchBackend {
+		cfg.DeepSeekBaseURL, cfg.DeepSeekAPIKey, cfg.DeepSeekModel = s.m.deepSeekSearchCreds()
+		wall = 120 * time.Second
+		// 搜索词由 DeepSeek 端的模型自行决定，"test" 太空泛会让它跳过搜索直接作答。
+		probeQuery = "DeepSeek company official website"
+	}
+	ctx, cancel := context.WithTimeout(r.Context(), wall)
 	defer cancel()
-	results, err := actool.WebSearchProbe(ctx, actool.WebSearchConfig{Backend: backend, BraveAPIKey: braveKey, TavilyAPIKey: tavilyKey, Proxy: proxy}, "test", 3)
+	results, err := actool.WebSearchProbe(ctx, cfg, probeQuery, 3)
 	if err != nil {
 		writeJSON(w, 200, map[string]any{"ok": false, "error": err.Error(), "backend": backend})
 		return