feat(ai): 阶段 2 Ask|Agent 共用 aitools Runtime 真查库

- 侧栏 Ask|Agent 分段；Ask 仍走 /api/ai/chat，Agent 走 /api/ai/agent
- RunAgent 多轮 tool call → 进程内 aitools（与 MCP 同源只读/白名单/审计）
- 回复下步骤时间线；openai-chat tools（DeepSeek）；agent-accept 冒烟

server/internal/ai/remote_tools.go

@@ -0,0 +1,143 @@
+package ai
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+
+	"opsxdb/server/internal/aitools"
+)
+
+// ToolsTurn 一轮带 tools 的模型回复：要么最终文本，要么一组 tool_calls。
+type ToolsTurn struct {
+	Content   string
+	ToolCalls []ToolCall
+	RawFinish string
+}
+
+// ToolChat 可挂载 tools 的 LLM（Agent 循环依赖此接口，便于单测注入）。
+type ToolChat interface {
+	ChatWithTools(ctx context.Context, model string, messages []Message, tools []aitools.OpenAITool) (ToolsTurn, error)
+}
+
+// ChatWithTools openai-chat 兼容协议的 tools 调用（DeepSeek / OpenAI / 多数兼容网关）。
+// anthropic / responses 本轮不支持 Agent tool calling，返回明确错误。
+func (p *RemoteProvider) ChatWithTools(ctx context.Context, model string, messages []Message, tools []aitools.OpenAITool) (ToolsTurn, error) {
+	if err := validateEndpoint(p.baseURL, p.allowHTTP); err != nil {
+		return ToolsTurn{}, err
+	}
+	if p.protocol != "" && p.protocol != ProtoChat {
+		return ToolsTurn{}, fmt.Errorf("Agent 模式目前仅支持 openai-chat 协议（当前: %s）；请改用 DeepSeek / OpenAI 兼容端点", p.protocol)
+	}
+	m := strings.TrimSpace(model)
+	if m == "" {
+		m = p.model
+	}
+	urlStr := endpoint(p.baseURL, "chat/completions")
+	payload := map[string]any{
+		"model":       m,
+		"messages":    messages,
+		"tools":       tools,
+		"tool_choice": "auto",
+		"max_tokens":  remoteMaxTokens,
+		"temperature": 0.2,
+	}
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return ToolsTurn{}, err
+	}
+	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, urlStr, bytes.NewReader(body))
+	if err != nil {
+		return ToolsTurn{}, err
+	}
+	httpReq.Header.Set("Content-Type", "application/json")
+	switch p.authStyle {
+	case AuthXAPIKey:
+		httpReq.Header.Set("x-api-key", p.apiKey)
+		httpReq.Header.Set("anthropic-version", "2023-06-01")
+	case AuthNone:
+	default:
+		httpReq.Header.Set("Authorization", "Bearer "+p.apiKey)
+	}
+	resp, err := p.hc.Do(httpReq)
+	if err != nil {
+		return ToolsTurn{}, fmt.Errorf("AI 请求失败: %w", err)
+	}
+	defer resp.Body.Close()
+	raw, err := io.ReadAll(io.LimitReader(resp.Body, 4<<20))
+	if err != nil {
+		return ToolsTurn{}, fmt.Errorf("读取 AI 响应失败: %w", err)
+	}
+	return parseToolsTurn(raw, resp.StatusCode)
+}
+
+func parseToolsTurn(raw []byte, status int) (ToolsTurn, error) {
+	var errBody struct {
+		Error *struct {
+			Message string `json:"message"`
+		} `json:"error"`
+		Message string `json:"message"`
+	}
+	_ = json.Unmarshal(raw, &errBody)
+	if status < 200 || status >= 300 {
+		msg := "未知错误"
+		if errBody.Error != nil && errBody.Error.Message != "" {
+			msg = errBody.Error.Message
+		} else if errBody.Message != "" {
+			msg = errBody.Message
+		}
+		return ToolsTurn{}, fmt.Errorf("AI 服务 HTTP %d: %s", status, msg)
+	}
+	var out struct {
+		Choices []struct {
+			FinishReason string `json:"finish_reason"`
+			Message      struct {
+				Role      string     `json:"role"`
+				Content   *string    `json:"content"`
+				ToolCalls []ToolCall `json:"tool_calls"`
+			} `json:"message"`
+		} `json:"choices"`
+		Error *struct {
+			Message string `json:"message"`
+		} `json:"error"`
+	}
+	if err := json.Unmarshal(raw, &out); err != nil {
+		return ToolsTurn{}, fmt.Errorf("解析 AI 响应失败(HTTP %d)", status)
+	}
+	if out.Error != nil {
+		return ToolsTurn{}, fmt.Errorf("AI 服务返回错误: %s", out.Error.Message)
+	}
+	if len(out.Choices) == 0 {
+		return ToolsTurn{}, fmt.Errorf("AI 服务未返回候选结果")
+	}
+	ch := out.Choices[0]
+	content := ""
+	if ch.Message.Content != nil {
+		content = strings.TrimSpace(*ch.Message.Content)
+	}
+	return ToolsTurn{
+		Content:   content,
+		ToolCalls: ch.Message.ToolCalls,
+		RawFinish: ch.FinishReason,
+	}, nil
+}
+
+// DefaultToolChat 返回可跑 Agent 的远端 Provider；stub / 缺 key 时返回错误说明。
+func DefaultToolChat() (ToolChat, error) {
+	cfg := LoadConfig()
+	if cfg.Provider == "" || cfg.Provider == "stub" {
+		return nil, fmt.Errorf("Agent 需要真实 LLM：请在设置中配置 DeepSeek / OpenAI 等（stub 仅支持 Ask 生成）")
+	}
+	if cfg.APIKey == "" && cfg.AuthStyle != AuthNone {
+		return nil, fmt.Errorf("Agent 需要 API Key：请在设置中填写后重试")
+	}
+	p := NewRemoteProvider(cfg)
+	if p.protocol != "" && p.protocol != ProtoChat {
+		return nil, fmt.Errorf("Agent 模式目前仅支持 openai-chat 协议（当前: %s）", p.protocol)
+	}
+	return p, nil
+}