feat(commands): 工具执行页新增调用次数统计

「工具执行」页工具栏加「统计」按钮，弹窗按工具展示调用次数、占比与
失败次数，按次数降序。统计沿用列表的 task/q 筛选，算的是整个结果集
而非当前页；弹窗打开时才请求，翻页不会多付一次聚合查询。

- db: 抽出 commandFilter,列表与统计共用同一份 WHERE;新增 ToolStats
- server: GET /api/commands/stats
- web: 统计弹窗 + demo 模式 mock

server/commands.go

@@ -15,14 +15,7 @@ func (s *Server) pgListCommands(w http.ResponseWriter, r *http.Request) {
 	size := atoiDefault(q.Get("size"), 50)
 	keyword := q.Get("q")
 
-	var expID *int64
-	if tv := q.Get("task"); tv != "" {
-		if n, err := strconv.ParseInt(tv, 10, 64); err == nil {
-			expID = &n
-		}
-	}
-
-	records, total, err := s.m.PG().ListCommands(expID, keyword, page, size)
+	records, total, err := s.m.PG().ListCommands(commandTaskFilter(q.Get("task")), keyword, page, size)
 	if err != nil {
 		writeErr(w, 500, err.Error())
 		return
@@ -30,6 +23,37 @@ func (s *Server) pgListCommands(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, 200, map[string]any{"commands": records, "total": total})
 }
 
+// pgToolStats returns per-tool call counts for the tool-execution history, under
+// the same task/keyword filters the list takes — the summary describes the whole
+// filtered set, not the page on screen.
+func (s *Server) pgToolStats(w http.ResponseWriter, r *http.Request) {
+	q := r.URL.Query()
+	pg := s.m.PG()
+	if pg == nil {
+		writeJSON(w, 200, map[string]any{"stats": []db.ToolStat{}})
+		return
+	}
+	stats, err := pg.ToolStats(commandTaskFilter(q.Get("task")), q.Get("q"))
+	if err != nil {
+		writeErr(w, 500, err.Error())
+		return
+	}
+	writeJSON(w, 200, map[string]any{"stats": stats})
+}
+
+// commandTaskFilter parses the ?task= exploration id. Absent or unparsable → nil
+// (no filter), matching the list endpoint's long-standing lenient behaviour.
+func commandTaskFilter(v string) *int64 {
+	if v == "" {
+		return nil
+	}
+	n, err := strconv.ParseInt(v, 10, 64)
+	if err != nil {
+		return nil
+	}
+	return &n
+}
+
 // pgListLLMRecords returns paginated LLM call records.
 func (s *Server) pgListLLMRecords(w http.ResponseWriter, r *http.Request) {
 	q := r.URL.Query()

server/server.go

@@ -787,6 +787,7 @@ func (s *Server) Handler() http.Handler {
 	mux.HandleFunc("GET /api/traffic/exchange", s.getTrafficExchange)
 	mux.HandleFunc("GET /api/traffic/blob", s.getTrafficBlob)
 	mux.HandleFunc("GET /api/commands", s.pgListCommands)
+	mux.HandleFunc("GET /api/commands/stats", s.pgToolStats) // 按工具聚合调用次数
 	mux.HandleFunc("GET /api/llm/records", s.pgListLLMRecords)
 	mux.HandleFunc("DELETE /api/llm/records", s.pgDeleteLLMRecords)
 	mux.HandleFunc("GET /api/llm/records/tasks", s.pgLLMTasks)