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/subsession/iot_provider.go

@@ -15,11 +15,11 @@ import (
 
 // IoTDeviceProvider IoT 设备查询接口
 type IoTDeviceProvider interface {
-	GetAllDevices() ([]tools.IoTDevice, error)
-	GetDevice(id string) (*tools.IoTDevice, error)
+	GetAllDevices(ctx context.Context) ([]tools.IoTDevice, error)
+	GetDevice(ctx context.Context, id string) (*tools.IoTDevice, error)
 	ToggleDevice(id string) error
 	SetDeviceProperty(id string, field string, value interface{}) error
-	GetDevicesForContext() []tools.IoTDevice
+	GetDevicesForContext(ctx context.Context) []tools.IoTDevice
 }
 
 // IoTProvider IoT 控制子会话提供者
@@ -75,7 +75,7 @@ func (p *IoTProvider) CreateContext(ctx context.Context, params CreateContextPar
 	// 获取当前设备状态
 	var deviceStatusText string
 	if p.iotClient != nil {
-		devices := p.iotClient.GetDevicesForContext()
+		devices := p.iotClient.GetDevicesForContext(ctx)
 		if len(devices) > 0 {
 			deviceStatusText = "当前设备状态：\n"
 			for _, d := range devices {
@@ -208,7 +208,7 @@ func (p *IoTProvider) Execute(ctx context.Context, subCtx []model.LLMMessage) (*
 	msgLower := strings.ToLower(userMessage)
 
 	// 尝试获取设备列表进行匹配
-	devices := p.iotClient.GetDevicesForContext()
+	devices := p.iotClient.GetDevicesForContext(ctx)
 
 	for _, dev := range devices {
 		devNameLower := strings.ToLower(dev.Name)

backend/ai-core/internal/subsession/manager.go

@@ -89,6 +89,11 @@ func (m *Manager) Dispatch(
 		wg.Add(1)
 		go func(p Provider) {
 			defer wg.Done()
+			defer func() {
+				if r := recover(); r != nil {
+					log.Printf("[subsession] dispatch goroutine panic 恢复 (type=%s): %v", p.Type(), r)
+				}
+			}()
 
 			result := model.SubSessionResult{Type: p.Type()}
 
@@ -135,6 +140,11 @@ func (m *Manager) Dispatch(
 
 	// 等待所有子会话完成，关闭通道
 	go func() {
+		defer func() {
+			if r := recover(); r != nil {
+				log.Printf("[subsession] wait goroutine panic 恢复: %v", r)
+			}
+		}()
 		wg.Wait()
 		close(resultCh)
 	}()