feat: 新增语音转文字（ASR）功能

- 后端：新增 /api/audio/transcribe 接口，调用 Ollama whisper 进行语音识别
- 前端：新增 AudioTranscribePage.vue 页面，支持 MP3/WAV/M4A/OGG/FLAC 等格式
- 注册路由、工具卡片、智能助手欢迎语更新

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

eai_agentplatform/backend-go/internal/model/course.go

@@ -0,0 +1,24 @@
+package model
+
+import "time"
+
+// Course 课程表
+type Course struct {
+	ID                 uint      `gorm:"primaryKey" json:"id"`
+	Code               string    `gorm:"size:32;uniqueIndex;not null" json:"code"`
+	Name               string    `gorm:"size:128;not null" json:"name"`
+	Category           string    `gorm:"size:32;not null;index" json:"category"` // capital_script/qualification_logic/ai_public_course/ai_platform_matching
+	TargetCustomers    string    `gorm:"type:text" json:"target_customers"`
+	ForbiddenCustomers string    `gorm:"type:text" json:"forbidden_customers"`
+	Scripts            string    `gorm:"type:text" json:"scripts"`
+	SalesProcess       string    `gorm:"type:text" json:"sales_process"`
+	ObjectionHandling  string    `gorm:"type:text" json:"objection_handling"`
+	DeliveryPitfalls   string    `gorm:"type:text" json:"delivery_pitfalls"`
+	ReportRules        string    `gorm:"type:text" json:"report_rules"`
+	RelatedProductID   *uint     `gorm:"index" json:"related_product_id"`
+	Status             string    `gorm:"size:16;not null;default:active;index" json:"status"` // active / inactive
+	CreatedAt          time.Time `json:"created_at"`
+	UpdatedAt          time.Time `json:"updated_at"`
+}
+
+func (Course) TableName() string { return "course" }