feat(ai): Agent SSE + Anthropic/responses tools + P1 确认写

- Agent 支持 SSE（步骤边推、正文分块），JSON 非流式 fallback
- tool calling 覆盖 openai-chat / anthropic / responses（单测解析回灌）
- P1：mcp.json mode=read_write 才可写；需 confirm_danger；Agent 剥离模型自带令牌
- GET /api/ai/mcp-status、POST /api/ai/agent/confirm；审计 source=mcp|agent

server/internal/aitools/status.go

@@ -0,0 +1,98 @@
+package aitools
+
+import (
+	"bufio"
+	"encoding/json"
+	"os"
+	"time"
+)
+
+const mcpActiveWindow = 5 * time.Minute
+
+// MCPStatus 供侧栏 MCP 状态点 / 设置页轻量指示。
+type MCPStatus struct {
+	Configured     bool         `json:"configured"`
+	Mode           string       `json:"mode"`
+	WhitelistCount int          `json:"whitelistCount"`
+	WritesEnabled  bool         `json:"writesEnabled"`
+	Active         bool         `json:"active"` // 近 5 分钟有 source=mcp 审计
+	Recent         []AuditEntry `json:"recent,omitempty"`
+	PolicyPath     string       `json:"policyPath,omitempty"`
+	AuditPath      string       `json:"auditPath,omitempty"`
+}
+
+// GetMCPStatus 读 mcp.json + 尾部审计；不探测外部 Cursor 进程。
+func GetMCPStatus() MCPStatus {
+	st := MCPStatus{Mode: ModeReadOnly}
+	if path, err := PolicyPath(); err == nil {
+		st.PolicyPath = path
+		if _, err := os.Stat(path); err == nil {
+			st.Configured = true
+		}
+	}
+	if p, err := LoadPolicy(); err == nil {
+		st.Mode = p.Mode
+		if st.Mode == "" {
+			st.Mode = ModeReadOnly
+		}
+		st.WhitelistCount = len(p.AllowedConnectionIDs)
+		st.WritesEnabled = p.WritesEnabled()
+		st.Configured = st.Configured || st.WhitelistCount > 0
+	}
+	if ap, err := AuditPath(); err == nil {
+		st.AuditPath = ap
+		recent := tailAudit(ap, 20)
+		st.Recent = filterSource(recent, "mcp")
+		if len(st.Recent) == 0 {
+			// 兼容旧审计无 source：仍展示最近条目，但不标 active
+			st.Recent = recent
+		} else {
+			cutoff := time.Now().Add(-mcpActiveWindow)
+			for _, e := range st.Recent {
+				if t, err := time.Parse(time.RFC3339, e.Time); err == nil && t.After(cutoff) {
+					st.Active = true
+					break
+				}
+			}
+		}
+	}
+	return st
+}
+
+func filterSource(in []AuditEntry, source string) []AuditEntry {
+	var out []AuditEntry
+	for _, e := range in {
+		if e.Source == source {
+			out = append(out, e)
+		}
+	}
+	return out
+}
+
+func tailAudit(path string, n int) []AuditEntry {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil
+	}
+	defer f.Close()
+	var lines []string
+	sc := bufio.NewScanner(f)
+	sc.Buffer(make([]byte, 0, 64*1024), 1024*1024)
+	for sc.Scan() {
+		lines = append(lines, sc.Text())
+		if len(lines) > n*4 { // 粗裁
+			lines = lines[len(lines)-n*2:]
+		}
+	}
+	if len(lines) > n {
+		lines = lines[len(lines)-n:]
+	}
+	out := make([]AuditEntry, 0, len(lines))
+	for _, line := range lines {
+		var e AuditEntry
+		if json.Unmarshal([]byte(line), &e) == nil {
+			out = append(out, e)
+		}
+	}
+	return out
+}