fix: 修复19个Bug (P0-P3) — 持续性调试第7轮发现的问题

P0 (5): crypto/rand session ID, TTS fallback可达性, goroutine defer recover, adminAuth前缀修正
P1 (5): 普通用户密码验证, context传递, priority clamp, 超时重试, 自主思考速率限制
P2 (4): Briefing AI降级, 前端消息类型渲染, Docker Compose补全, PWA 192图标
P3 (5): goroutine错误处理, .gitignore完善, reminder created_at, voice Dockerfile, Go版本更新

backend/ai-core/internal/tools/iot_tools.go

@@ -47,7 +47,7 @@ func (t *IoTQueryTool) Execute(ctx context.Context, arguments map[string]interfa
 
 	if deviceID != "" {
 		// 查询单个设备
-		device, err := t.iotClient.GetDevice(deviceID)
+		device, err := t.iotClient.GetDevice(ctx, deviceID)
 		if err != nil {
 			return &ToolResult{
 				ToolName: "iot_query",
@@ -63,7 +63,7 @@ func (t *IoTQueryTool) Execute(ctx context.Context, arguments map[string]interfa
 	}
 
 	// 查询所有设备
-	devices, err := t.iotClient.GetAllDevices()
+	devices, err := t.iotClient.GetAllDevices(ctx)
 	if err != nil {
 		return &ToolResult{
 			ToolName: "iot_query",