feat: add priority demotion controls

apps/api/internal/httpapi/runtime_policy_handlers.go

@@ -44,6 +44,44 @@ func (s *Server) updateRunnerPolicy(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, item)
 }
 
+type updatePlatformDynamicPriorityRequest struct {
+	DynamicPriority *int `json:"dynamicPriority"`
+	Reset           bool `json:"reset"`
+}
+
+func (s *Server) updatePlatformDynamicPriority(w http.ResponseWriter, r *http.Request) {
+	var input updatePlatformDynamicPriorityRequest
+	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid json body")
+		return
+	}
+	var dynamicPriority *int
+	if input.Reset {
+		dynamicPriority = nil
+	} else {
+		if input.DynamicPriority == nil {
+			writeError(w, http.StatusBadRequest, "dynamicPriority is required unless reset is true")
+			return
+		}
+		if *input.DynamicPriority < 0 {
+			writeError(w, http.StatusBadRequest, "dynamicPriority must be greater than or equal to 0")
+			return
+		}
+		dynamicPriority = input.DynamicPriority
+	}
+	item, err := s.store.UpdatePlatformDynamicPriority(r.Context(), r.PathValue("platformID"), dynamicPriority)
+	if err != nil {
+		if store.IsNotFound(err) {
+			writeError(w, http.StatusNotFound, "platform not found")
+			return
+		}
+		s.logger.Error("update platform dynamic priority failed", "error", err)
+		writeError(w, http.StatusInternalServerError, "update platform dynamic priority failed")
+		return
+	}
+	writeJSON(w, http.StatusOK, item)
+}
+
 func (s *Server) createRuntimePolicySet(w http.ResponseWriter, r *http.Request) {
 	var input store.RuntimePolicySetInput
 	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {