feat: add agentmon services section to infrastructure page

Label all agentmon docker-compose services with agentmon.monitor=true
and agentmon.group=agentmon so the swarm-monitor picks them up.
Adds Group field to ServiceSnapshot, probes /healthz for api/web roles,
and renders a separate "Agentmon" section below Swarm Services on the
Infrastructure page with new api and worker card renderers.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cmd/query-api/main.go

@@ -218,6 +218,19 @@ func main() {
 		httpx.WriteJSON(w, http.StatusOK, summary)
 	})
 
+	r.Get("/v1/stats/top-tools", func(w http.ResponseWriter, r *http.Request) {
+		limit, _ := strconv.Atoi(r.URL.Query().Get("limit"))
+		tools, err := db.GetTopTools(r.Context(), limit)
+		if err != nil {
+			httpx.WriteJSON(w, http.StatusInternalServerError, map[string]any{"error": "db_error"})
+			return
+		}
+		if tools == nil {
+			tools = []postgres.TopTool{}
+		}
+		httpx.WriteJSON(w, http.StatusOK, map[string]any{"tools": tools})
+	})
+
 	r.Get("/v1/stats/timeseries", func(w http.ResponseWriter, r *http.Request) {
 		window := r.URL.Query().Get("window")
 		switch window {