merge: integrate upstream v0.1.95 with our customizations

Merge main (custom features) into release/custom-0.1.95 (upstream v0.1.95).
New upstream features: group subscription binding, multi-dimension quota (daily/weekly/total),
allow_messages_dispatch, default_mapped_model, recover state API.
Our customizations: simulate_claude_max_enabled, usage status detection, 403 validation handling.

backend/internal/handler/gateway_handler.go

@@ -439,6 +439,7 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 			h.submitUsageRecordTask(func(ctx context.Context) {
 				if err := h.gatewayService.RecordUsage(ctx, &service.RecordUsageInput{
 					Result:            result,
+					ParsedRequest:     parsedReq,
 					APIKey:            apiKey,
 					User:              apiKey.User,
 					Account:           account,
@@ -630,6 +631,7 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 			// ===== 用户消息串行队列 END =====
 
 			// 转发请求 - 根据账号平台分流
+			c.Set("parsed_request", parsedReq)
 			var result *service.ForwardResult
 			requestCtx := c.Request.Context()
 			if fs.SwitchCount > 0 {
@@ -741,6 +743,7 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 			h.submitUsageRecordTask(func(ctx context.Context) {
 				if err := h.gatewayService.RecordUsage(ctx, &service.RecordUsageInput{
 					Result:            result,
+					ParsedRequest:     parsedReq,
 					APIKey:            currentAPIKey,
 					User:              currentAPIKey.User,
 					Account:           account,