feat: 实现自建情景功能

## 功能概述
- 用户可创建、编辑、删除自定义情景
- 支持自定义情景名称、图标、描述、Prompt、首句引导
- 完整的权限隔离，用户只能管理自己的情景
- 深度集成 Eino 框架，动态加载自建情景 Prompt

## 后端实现
### 数据库
- 新增 user_scenarios 表
- 支持用户配额（最多 20 个）
- 字段验证：description 可选，prompt 最小 10 字符

### API
- GET /api/scenarios - 获取用户情景列表
- POST /api/scenarios - 创建情景
- GET /api/scenarios/:id - 获取详情
- PATCH /api/scenarios/:id - 更新情景
- DELETE /api/scenarios/:id - 删除情景

### Eino 集成
- PipelineState 添加 UserID 字段
- nodes_history 动态加载用户自建情景
- GetScenarioPrompt 支持自建情景优先级

## 前端实现
### 组件
- CreateScenarioModal - 创建情景对话框
- EditScenarioModal - 编辑情景对话框
- ConfigPanel 改造 - 分组显示系统预置和自建情景

### Hook
- useScenarios - 合并系统和自建情景，提供 CRUD 接口

### 国际化
- 中文、英文、日文翻译支持

## 问题修复
- 修复 CORS 问题：使用 Vite 代理
- 统一验证规则：description 可选，prompt 最小 10 字符
- 修复数据库约束：使用 NULLIF 处理空字符串

## 文件变更
新增文件: 13 个
修改文件: 14 个

详见文档: docs/自建情景功能完整文档.md

backend/cmd/server/main.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/gin-gonic/gin"
+	"github.com/jackc/pgx/v5/pgxpool"
 	"github.com/redis/go-redis/v9"
 
 	"github.com/hhs/camtalk/internal/api"
@@ -54,6 +55,7 @@ func main() {
 	var userRepo store.UserRepository
 	var msgRepo store.MessageRepository
 	var sessRepo store.SessionRepository
+	var pool *pgxpool.Pool // 数据库连接池
 
 	// L3: PostgreSQL（冷数据持久化层）
 	dsn := cfg.Storage.Persistence.DSN
@@ -65,7 +67,8 @@ func main() {
 			logger.Log.Fatalw("storage.persistence.dsn is required when persistence is enabled",
 				"hint", "set CAMTALK_STORAGE_DSN environment variable")
 		}
-		pool, err := store.NewPostgresPool(ctx, dsn)
+		var err error
+		pool, err = store.NewPostgresPool(ctx, dsn)
 		if err != nil {
 			logger.Log.Fatalw("failed to connect to postgres", "error", err)
 		}
@@ -181,7 +184,11 @@ func main() {
 	}
 
 	// 初始化 Eino Graph + Orchestrator
-	pipelineGraph, err := eino.NewPipelineGraph(ctx, cfg, sttService, ttsService, sessionMgr)
+	var userScenarioRepo store.UserScenarioRepository
+	if pool != nil {
+		userScenarioRepo = store.NewPostgresUserScenarioRepo(pool)
+	}
+	pipelineGraph, err := eino.NewPipelineGraph(ctx, cfg, sttService, ttsService, sessionMgr, userScenarioRepo)
 	if err != nil {
 		logger.Log.Fatalw("failed to create eino pipeline graph", "error", err)
 	}
@@ -221,8 +228,23 @@ func main() {
 	convHandler := api.NewConversationHandler(sessionMgr, tokenMgr, msgRepo)
 	convHandler.RegisterRoutes(apiGroup)
 
+	// UserScenario REST 端点
+	if pool != nil {
+		userScenarioRepo := store.NewPostgresUserScenarioRepo(pool)
+		userScenarioHandler := api.NewUserScenarioHandler(userScenarioRepo)
+		scenarioGroup := apiGroup.Group("/scenarios")
+		scenarioGroup.Use(auth.AuthMiddleware(tokenMgr))
+		{
+			scenarioGroup.GET("", userScenarioHandler.List)
+			scenarioGroup.POST("", userScenarioHandler.Create)
+			scenarioGroup.GET("/:id", userScenarioHandler.Get)
+			scenarioGroup.PATCH("/:id", userScenarioHandler.Update)
+			scenarioGroup.DELETE("/:id", userScenarioHandler.Delete)
+		}
+	}
+
 	// WebSocket
-	r.GET("/ws", ws.ServeWS(sessionMgr, orch, cfg, tokenMgr))
+	r.GET("/ws", ws.ServeWS(sessionMgr, orch, cfg, tokenMgr, userScenarioRepo))
 
 	// HTTP Server
 	srv := &http.Server{

backend/internal/ai/llm/scenarios.go

@@ -84,41 +84,65 @@ var scenarioPrompts = map[string]scenarioPrompt{
 }
 
 // GetScenarioPrompt 根据情景 ID 和语言获取对应的 system prompt。
+// 支持系统预置情景和用户自建情景。
+// customScenarios: 用户自建情景映射表（scenarioID → prompt），可为 nil
 // 返回空字符串表示无此情景（使用默认 prompt）。
-func GetScenarioPrompt(scenarioID, language string) string {
+func GetScenarioPrompt(scenarioID, language string, customScenarios map[string]string) string {
 	if scenarioID == "" || scenarioID == "free_chat" {
 		return ""
 	}
-	p, ok := scenarioPrompts[scenarioID]
-	if !ok {
-		return ""
+
+	// 1. 优先查找系统预置情景
+	if p, ok := scenarioPrompts[scenarioID]; ok {
+		switch {
+		case strings.HasPrefix(language, "zh"):
+			return p.ZH
+		case strings.HasPrefix(language, "ja"):
+			return p.JA
+		default:
+			return p.EN
+		}
 	}
-	switch {
-	case strings.HasPrefix(language, "zh"):
-		return p.ZH
-	case strings.HasPrefix(language, "ja"):
-		return p.JA
-	default:
-		return p.EN
+
+	// 2. 查找用户自建情景
+	if customScenarios != nil {
+		if customPrompt, ok := customScenarios[scenarioID]; ok {
+			return customPrompt
+		}
 	}
+
+	// 3. 默认空字符串
+	return ""
 }
 
 // GetScenarioGreeting 根据情景 ID 和语言获取对应的首句引导。
+// 支持系统预置情景和用户自建情景。
+// customGreetings: 用户自建情景的首句引导映射表（scenarioID → greeting），可为 nil
 // 返回空字符串表示无此情景或不需要引导（自由对话）。
-func GetScenarioGreeting(scenarioID, language string) string {
+func GetScenarioGreeting(scenarioID, language string, customGreetings map[string]string) string {
 	if scenarioID == "" || scenarioID == "free_chat" {
 		return ""
 	}
-	p, ok := scenarioPrompts[scenarioID]
-	if !ok {
-		return ""
+
+	// 1. 优先查找系统预置情景
+	if p, ok := scenarioPrompts[scenarioID]; ok {
+		switch {
+		case strings.HasPrefix(language, "zh"):
+			return p.GreetingZH
+		case strings.HasPrefix(language, "ja"):
+			return p.GreetingJA
+		default:
+			return p.GreetingEN
+		}
 	}
-	switch {
-	case strings.HasPrefix(language, "zh"):
-		return p.GreetingZH
-	case strings.HasPrefix(language, "ja"):
-		return p.GreetingJA
-	default:
-		return p.GreetingEN
+
+	// 2. 查找用户自建情景
+	if customGreetings != nil {
+		if customGreeting, ok := customGreetings[scenarioID]; ok {
+			return customGreeting
+		}
 	}
+
+	// 3. 默认空字符串
+	return ""
 }

backend/internal/api/user_scenario_handler.go

@@ -0,0 +1,208 @@
+package api
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+
+	"github.com/hhs/camtalk/internal/logger"
+	"github.com/hhs/camtalk/internal/models"
+	"github.com/hhs/camtalk/internal/store"
+)
+
+const (
+	MaxScenariosPerUser = 20   // 每个用户最多 20 个自建情景
+	MaxPromptLength     = 2000 // Prompt 最大长度
+)
+
+// UserScenarioHandler 用户情景 API Handler。
+type UserScenarioHandler struct {
+	repo store.UserScenarioRepository
+}
+
+// NewUserScenarioHandler 创建用户情景 Handler。
+func NewUserScenarioHandler(repo store.UserScenarioRepository) *UserScenarioHandler {
+	return &UserScenarioHandler{repo: repo}
+}
+
+// List 获取用户的所有自建情景。
+// GET /api/scenarios
+func (h *UserScenarioHandler) List(c *gin.Context) {
+	userID, exists := c.Get("user_id")
+	if !exists {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
+		return
+	}
+
+	scenarios, err := h.repo.FindByUserID(c.Request.Context(), userID.(string))
+	if err != nil {
+		logger.Log.Errorw("查询用户情景失败", "user_id", userID, "error", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "查询失败"})
+		return
+	}
+
+	if scenarios == nil {
+		scenarios = []*models.UserScenario{}
+	}
+
+	c.JSON(http.StatusOK, models.UserScenarioListResponse{
+		Scenarios: scenarios,
+		Total:     len(scenarios),
+	})
+}
+
+// Create 创建用户情景。
+// POST /api/scenarios
+func (h *UserScenarioHandler) Create(c *gin.Context) {
+	userID, exists := c.Get("user_id")
+	if !exists {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
+		return
+	}
+
+	var req models.CreateUserScenarioRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "参数错误: " + err.Error()})
+		return
+	}
+
+	// 检查用户是否已达上限
+	count, err := h.repo.CountByUserID(c.Request.Context(), userID.(string))
+	if err != nil {
+		logger.Log.Errorw("统计用户情景数量失败", "user_id", userID, "error", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "创建失败"})
+		return
+	}
+	if count >= MaxScenariosPerUser {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "已达创建上限（最多 20 个）"})
+		return
+	}
+
+	// 创建情景
+	scenario := &models.UserScenario{
+		UserID:      userID.(string),
+		Name:        req.Name,
+		Icon:        req.Icon,
+		Description: req.Description,
+		Prompt:      req.Prompt,
+		Greeting:    req.Greeting,
+		Language:    req.Language,
+	}
+
+	if err := h.repo.Create(c.Request.Context(), scenario); err != nil {
+		logger.Log.Errorw("创建用户情景失败", "user_id", userID, "error", err)
+		if err.Error() == "duplicate key value violates unique constraint" {
+			c.JSON(http.StatusBadRequest, gin.H{"error": "情景名称已存在"})
+			return
+		}
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "创建失败"})
+		return
+	}
+
+	logger.Log.Infow("创建用户情景成功", "user_id", userID, "scenario_id", scenario.ID)
+	c.JSON(http.StatusCreated, scenario)
+}
+
+// Get 获取单个情景详情。
+// GET /api/scenarios/:id
+func (h *UserScenarioHandler) Get(c *gin.Context) {
+	userID, exists := c.Get("user_id")
+	if !exists {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
+		return
+	}
+
+	scenarioID := c.Param("id")
+	scenario, err := h.repo.FindByIDAndUserID(c.Request.Context(), scenarioID, userID.(string))
+	if err != nil {
+		logger.Log.Errorw("查询用户情景失败", "user_id", userID, "scenario_id", scenarioID, "error", err)
+		c.JSON(http.StatusNotFound, gin.H{"error": "情景不存在或无权限"})
+		return
+	}
+
+	c.JSON(http.StatusOK, scenario)
+}
+
+// Update 更新用户情景。
+// PATCH /api/scenarios/:id
+func (h *UserScenarioHandler) Update(c *gin.Context) {
+	userID, exists := c.Get("user_id")
+	if !exists {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
+		return
+	}
+
+	scenarioID := c.Param("id")
+
+	// 查询并校验所有权
+	scenario, err := h.repo.FindByIDAndUserID(c.Request.Context(), scenarioID, userID.(string))
+	if err != nil {
+		logger.Log.Errorw("查询用户情景失败", "user_id", userID, "scenario_id", scenarioID, "error", err)
+		c.JSON(http.StatusNotFound, gin.H{"error": "情景不存在或无权限"})
+		return
+	}
+
+	var req models.UpdateUserScenarioRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "参数错误: " + err.Error()})
+		return
+	}
+
+	// 更新字段
+	if req.Name != nil {
+		scenario.Name = *req.Name
+	}
+	if req.Icon != nil {
+		scenario.Icon = *req.Icon
+	}
+	if req.Description != nil {
+		scenario.Description = *req.Description
+	}
+	if req.Prompt != nil {
+		scenario.Prompt = *req.Prompt
+	}
+	if req.Greeting != nil {
+		scenario.Greeting = *req.Greeting
+	}
+	if req.Language != nil {
+		scenario.Language = *req.Language
+	}
+
+	if err := h.repo.Update(c.Request.Context(), scenario); err != nil {
+		logger.Log.Errorw("更新用户情景失败", "user_id", userID, "scenario_id", scenarioID, "error", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "更新失败"})
+		return
+	}
+
+	logger.Log.Infow("更新用户情景成功", "user_id", userID, "scenario_id", scenarioID)
+	c.JSON(http.StatusOK, scenario)
+}
+
+// Delete 删除用户情景。
+// DELETE /api/scenarios/:id
+func (h *UserScenarioHandler) Delete(c *gin.Context) {
+	userID, exists := c.Get("user_id")
+	if !exists {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "未登录"})
+		return
+	}
+
+	scenarioID := c.Param("id")
+
+	// 查询并校验所有权
+	_, err := h.repo.FindByIDAndUserID(c.Request.Context(), scenarioID, userID.(string))
+	if err != nil {
+		logger.Log.Errorw("查询用户情景失败", "user_id", userID, "scenario_id", scenarioID, "error", err)
+		c.JSON(http.StatusNotFound, gin.H{"error": "情景不存在或无权限"})
+		return
+	}
+
+	if err := h.repo.Delete(c.Request.Context(), scenarioID); err != nil {
+		logger.Log.Errorw("删除用户情景失败", "user_id", userID, "scenario_id", scenarioID, "error", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "删除失败"})
+		return
+	}
+
+	logger.Log.Infow("删除用户情景成功", "user_id", userID, "scenario_id", scenarioID)
+	c.Status(http.StatusNoContent)
+}

backend/internal/eino/adapter.go

@@ -119,6 +119,7 @@ func (e *EinoOrchestrator) ProcessQuery(
 	state.Language = input.Language
 	state.DetailLevel = sess.Config.DetailLevel
 	state.TTSEnabled = input.TTSEnabled
+	state.UserID = input.UserID
 	ctx = WithPipelineState(ctx, state)
 
 	// 6. 调用 Graph（Stream 模式 + 运行时 Callback）

backend/internal/eino/graph.go

@@ -13,6 +13,7 @@ import (
 	"github.com/hhs/camtalk/internal/logger"
 	"github.com/hhs/camtalk/internal/models"
 	"github.com/hhs/camtalk/internal/session"
+	"github.com/hhs/camtalk/internal/store"
 )
 
 const (
@@ -42,6 +43,7 @@ func NewPipelineGraph(
 	sttService stt.Service,
 	ttsService tts.Service,
 	sessionMgr session.Manager,
+	scenarioRepo store.UserScenarioRepository,
 ) (*PipelineGraph, error) {
 	log := logger.Log
 
@@ -68,7 +70,7 @@ func NewPipelineGraph(
 	maxHistory := cfg.Session.MaxHistory
 
 	_ = g.AddLambdaNode(nodeSTT, NewSTTLambda(sttService))
-	_ = g.AddLambdaNode(nodeHistory, NewHistoryLambda(sessionMgr.GetHistory, maxHistory))
+	_ = g.AddLambdaNode(nodeHistory, NewHistoryLambda(sessionMgr.GetHistory, scenarioRepo, maxHistory))
 	_ = g.AddChatModelNode(nodeLLM, chatModel)
 	_ = g.AddLambdaNode(nodeMessageToString, NewMessageToStringLambda())
 	_ = g.AddLambdaNode(nodeSplitter, NewSplitterLambda())
@@ -112,5 +114,6 @@ func buildPipelineInput(req models.WsQuery, sessionID string, sess *models.Sessi
 		Language:   sess.Config.Language,
 		Scenario:   sess.Config.Scenario,
 		TTSEnabled: sess.Config.TTSEnabled,
+		UserID:     sess.UserID,
 	}
 }

backend/internal/eino/nodes_history.go

@@ -10,6 +10,7 @@ import (
 	"github.com/hhs/camtalk/internal/ai/llm"
 	"github.com/hhs/camtalk/internal/logger"
 	"github.com/hhs/camtalk/internal/models"
+	"github.com/hhs/camtalk/internal/store"
 )
 
 // NewHistoryLambda 创建历史组装 Lambda 节点。
@@ -17,7 +18,11 @@ import (
 //
 // 从 PipelineState 读取请求元数据（SessionID、Scenario、ImageData 等），
 // 构建系统提示词，组装历史消息和当前用户输入（含多模态图片）。
-func NewHistoryLambda(historyFetcher func(ctx context.Context, sessionID string, limit int) ([]models.Message, error), maxHistory int) *compose.Lambda {
+func NewHistoryLambda(
+	historyFetcher func(ctx context.Context, sessionID string, limit int) ([]models.Message, error),
+	scenarioRepo store.UserScenarioRepository,
+	maxHistory int,
+) *compose.Lambda {
 	return compose.InvokableLambda(func(ctx context.Context, sttOut STTOutput) ([]*schema.Message, error) {
 		log := logger.Log
 
@@ -34,10 +39,31 @@ func NewHistoryLambda(historyFetcher func(ctx context.Context, sessionID string,
 		scenario := state.Scenario
 		detailLevel := state.DetailLevel
 		language := sttOut.Language
+		userID := state.UserID
 		state.mu.Unlock()
 
-		// 构建系统提示词
-		scenarioPrompt := llm.GetScenarioPrompt(scenario, language)
+		// 加载用户自建情景（如果有 userID 和 scenarioRepo）
+		var customScenarios map[string]string
+		var customGreetings map[string]string
+		if userID != "" && scenarioRepo != nil {
+			scenarios, err := scenarioRepo.FindByUserID(ctx, userID)
+			if err != nil {
+				log.Warnw("加载用户自建情景失败", "user_id", userID, "error", err)
+			} else if len(scenarios) > 0 {
+				customScenarios = make(map[string]string, len(scenarios))
+				customGreetings = make(map[string]string, len(scenarios))
+				for _, s := range scenarios {
+					customScenarios[s.ID] = s.Prompt
+					if s.Greeting != "" {
+						customGreetings[s.ID] = s.Greeting
+					}
+				}
+				log.Debugw("加载用户自建情景", "user_id", userID, "count", len(scenarios))
+			}
+		}
+
+		// 构建系统提示词（支持用户自建情景）
+		scenarioPrompt := llm.GetScenarioPrompt(scenario, language, customScenarios)
 		systemPrompt := llm.BuildSystemPrompt(language, detailLevel, scenarioPrompt)
 
 		// 构建 system message（仅文本，多模态内容只能放在 user 角色）

backend/internal/eino/state.go

@@ -23,6 +23,7 @@ type PipelineState struct {
 	DetailLevel string
 	Language    string
 	TTSEnabled  bool
+	UserID      string // 新增：用户 ID，用于加载自建情景
 }
 
 // genLocalState 创建每请求的 PipelineState 实例。

backend/internal/eino/types.go

@@ -12,6 +12,7 @@ type PipelineInput struct {
 	Language   string // zh / en
 	Scenario   string // free_chat, interviewer, etc.
 	TTSEnabled bool
+	UserID     string // 用户 ID，用于加载自建情景
 }
 
 // PipelineOutput Graph 统一输出。

backend/internal/models/user_scenario.go

@@ -0,0 +1,43 @@
+package models
+
+import "time"
+
+// UserScenario 用户自建情景。
+type UserScenario struct {
+	ID          string    `json:"id"`
+	UserID      string    `json:"user_id"`
+	Name        string    `json:"name"`
+	Icon        string    `json:"icon"`
+	Description string    `json:"description"`
+	Prompt      string    `json:"prompt"`
+	Greeting    string    `json:"greeting,omitempty"`
+	Language    string    `json:"language"`
+	CreatedAt   time.Time `json:"created_at"`
+	UpdatedAt   time.Time `json:"updated_at"`
+}
+
+// CreateUserScenarioRequest 创建用户情景请求。
+type CreateUserScenarioRequest struct {
+	Name        string `json:"name" binding:"required,min=2,max=50"`
+	Icon        string `json:"icon,omitempty"`
+	Description string `json:"description,omitempty" binding:"omitempty,max=100"`
+	Prompt      string `json:"prompt" binding:"required,min=10,max=2000"`
+	Greeting    string `json:"greeting,omitempty" binding:"omitempty,max=500"`
+	Language    string `json:"language,omitempty"`
+}
+
+// UpdateUserScenarioRequest 更新用户情景请求。
+type UpdateUserScenarioRequest struct {
+	Name        *string `json:"name,omitempty" binding:"omitempty,min=2,max=50"`
+	Icon        *string `json:"icon,omitempty"`
+	Description *string `json:"description,omitempty" binding:"omitempty,max=100"`
+	Prompt      *string `json:"prompt,omitempty" binding:"omitempty,min=10,max=2000"`
+	Greeting    *string `json:"greeting,omitempty" binding:"omitempty,max=500"`
+	Language    *string `json:"language,omitempty"`
+}
+
+// UserScenarioListResponse 用户情景列表响应。
+type UserScenarioListResponse struct {
+	Scenarios []*UserScenario `json:"scenarios"`
+	Total     int             `json:"total"`
+}

backend/internal/store/user_scenario_repository.go

@@ -0,0 +1,238 @@
+package store
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgxpool"
+
+	"github.com/hhs/camtalk/internal/models"
+)
+
+// UserScenarioRepository 用户自建情景仓储接口。
+type UserScenarioRepository interface {
+	Create(ctx context.Context, scenario *models.UserScenario) error
+	FindByID(ctx context.Context, id string) (*models.UserScenario, error)
+	FindByIDAndUserID(ctx context.Context, id, userID string) (*models.UserScenario, error)
+	FindByUserID(ctx context.Context, userID string) ([]*models.UserScenario, error)
+	Update(ctx context.Context, scenario *models.UserScenario) error
+	Delete(ctx context.Context, id string) error
+	CountByUserID(ctx context.Context, userID string) (int, error)
+}
+
+// PostgresUserScenarioRepo PostgreSQL 实现。
+type PostgresUserScenarioRepo struct {
+	pool *pgxpool.Pool
+}
+
+// NewPostgresUserScenarioRepo 创建 PostgreSQL 用户情景仓储。
+func NewPostgresUserScenarioRepo(pool *pgxpool.Pool) UserScenarioRepository {
+	return &PostgresUserScenarioRepo{pool: pool}
+}
+
+// Create 创建用户情景。
+func (r *PostgresUserScenarioRepo) Create(ctx context.Context, scenario *models.UserScenario) error {
+	query := `
+		INSERT INTO user_scenarios (id, user_id, name, icon, description, prompt, greeting, language, created_at, updated_at)
+		VALUES ($1, $2, $3, $4, NULLIF($5, ''), $6, NULLIF($7, ''), $8, $9, $10)
+		RETURNING id, created_at, updated_at
+	`
+
+	now := time.Now()
+	scenario.CreatedAt = now
+	scenario.UpdatedAt = now
+
+	if scenario.ID == "" {
+		scenario.ID = uuid.New().String()
+	}
+	if scenario.Icon == "" {
+		scenario.Icon = "✨"
+	}
+	if scenario.Language == "" {
+		scenario.Language = "zh-CN"
+	}
+
+	err := r.pool.QueryRow(ctx, query,
+		scenario.ID,
+		scenario.UserID,
+		scenario.Name,
+		scenario.Icon,
+		scenario.Description,
+		scenario.Prompt,
+		scenario.Greeting,
+		scenario.Language,
+		scenario.CreatedAt,
+		scenario.UpdatedAt,
+	).Scan(&scenario.ID, &scenario.CreatedAt, &scenario.UpdatedAt)
+
+	if err != nil {
+		return fmt.Errorf("create user scenario: %w", err)
+	}
+	return nil
+}
+
+// FindByID 根据 ID 查找情景。
+func (r *PostgresUserScenarioRepo) FindByID(ctx context.Context, id string) (*models.UserScenario, error) {
+	query := `
+		SELECT id, user_id, name, icon, description, prompt, greeting, language, created_at, updated_at
+		FROM user_scenarios
+		WHERE id = $1
+	`
+
+	var scenario models.UserScenario
+	err := r.pool.QueryRow(ctx, query, id).Scan(
+		&scenario.ID,
+		&scenario.UserID,
+		&scenario.Name,
+		&scenario.Icon,
+		&scenario.Description,
+		&scenario.Prompt,
+		&scenario.Greeting,
+		&scenario.Language,
+		&scenario.CreatedAt,
+		&scenario.UpdatedAt,
+	)
+
+	if err == pgx.ErrNoRows {
+		return nil, fmt.Errorf("user scenario not found: %s", id)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("find user scenario: %w", err)
+	}
+	return &scenario, nil
+}
+
+// FindByIDAndUserID 根据 ID 和用户 ID 查找情景（权限校验）。
+func (r *PostgresUserScenarioRepo) FindByIDAndUserID(ctx context.Context, id, userID string) (*models.UserScenario, error) {
+	query := `
+		SELECT id, user_id, name, icon, description, prompt, greeting, language, created_at, updated_at
+		FROM user_scenarios
+		WHERE id = $1 AND user_id = $2
+	`
+
+	var scenario models.UserScenario
+	err := r.pool.QueryRow(ctx, query, id, userID).Scan(
+		&scenario.ID,
+		&scenario.UserID,
+		&scenario.Name,
+		&scenario.Icon,
+		&scenario.Description,
+		&scenario.Prompt,
+		&scenario.Greeting,
+		&scenario.Language,
+		&scenario.CreatedAt,
+		&scenario.UpdatedAt,
+	)
+
+	if err == pgx.ErrNoRows {
+		return nil, fmt.Errorf("user scenario not found or no permission")
+	}
+	if err != nil {
+		return nil, fmt.Errorf("find user scenario: %w", err)
+	}
+	return &scenario, nil
+}
+
+// FindByUserID 查找用户的所有情景。
+func (r *PostgresUserScenarioRepo) FindByUserID(ctx context.Context, userID string) ([]*models.UserScenario, error) {
+	query := `
+		SELECT id, user_id, name, icon, description, prompt, greeting, language, created_at, updated_at
+		FROM user_scenarios
+		WHERE user_id = $1
+		ORDER BY created_at DESC
+	`
+
+	rows, err := r.pool.Query(ctx, query, userID)
+	if err != nil {
+		return nil, fmt.Errorf("find user scenarios: %w", err)
+	}
+	defer rows.Close()
+
+	var scenarios []*models.UserScenario
+	for rows.Next() {
+		var s models.UserScenario
+		err := rows.Scan(
+			&s.ID,
+			&s.UserID,
+			&s.Name,
+			&s.Icon,
+			&s.Description,
+			&s.Prompt,
+			&s.Greeting,
+			&s.Language,
+			&s.CreatedAt,
+			&s.UpdatedAt,
+		)
+		if err != nil {
+			return nil, fmt.Errorf("scan user scenario: %w", err)
+		}
+		scenarios = append(scenarios, &s)
+	}
+
+	if err = rows.Err(); err != nil {
+		return nil, fmt.Errorf("iterate user scenarios: %w", err)
+	}
+	return scenarios, nil
+}
+
+// Update 更新用户情景。
+func (r *PostgresUserScenarioRepo) Update(ctx context.Context, scenario *models.UserScenario) error {
+	query := `
+		UPDATE user_scenarios
+		SET name = $1, icon = $2, description = $3, prompt = $4, greeting = $5, language = $6, updated_at = $7
+		WHERE id = $8 AND user_id = $9
+		RETURNING updated_at
+	`
+
+	scenario.UpdatedAt = time.Now()
+
+	err := r.pool.QueryRow(ctx, query,
+		scenario.Name,
+		scenario.Icon,
+		scenario.Description,
+		scenario.Prompt,
+		scenario.Greeting,
+		scenario.Language,
+		scenario.UpdatedAt,
+		scenario.ID,
+		scenario.UserID,
+	).Scan(&scenario.UpdatedAt)
+
+	if err == pgx.ErrNoRows {
+		return fmt.Errorf("user scenario not found or no permission")
+	}
+	if err != nil {
+		return fmt.Errorf("update user scenario: %w", err)
+	}
+	return nil
+}
+
+// Delete 删除用户情景。
+func (r *PostgresUserScenarioRepo) Delete(ctx context.Context, id string) error {
+	query := `DELETE FROM user_scenarios WHERE id = $1`
+
+	result, err := r.pool.Exec(ctx, query, id)
+	if err != nil {
+		return fmt.Errorf("delete user scenario: %w", err)
+	}
+
+	if result.RowsAffected() == 0 {
+		return fmt.Errorf("user scenario not found")
+	}
+	return nil
+}
+
+// CountByUserID 统计用户的情景数量。
+func (r *PostgresUserScenarioRepo) CountByUserID(ctx context.Context, userID string) (int, error) {
+	query := `SELECT COUNT(*) FROM user_scenarios WHERE user_id = $1`
+
+	var count int
+	err := r.pool.QueryRow(ctx, query, userID).Scan(&count)
+	if err != nil {
+		return 0, fmt.Errorf("count user scenarios: %w", err)
+	}
+	return count, nil
+}

backend/internal/ws/handler.go

@@ -18,6 +18,7 @@ import (
 	"github.com/hhs/camtalk/internal/models"
 	"github.com/hhs/camtalk/internal/orchestrator"
 	"github.com/hhs/camtalk/internal/session"
+	"github.com/hhs/camtalk/internal/store"
 )
 
 // newUpgrader 根据配置创建 WebSocket upgrader。
@@ -93,19 +94,19 @@ func (w *WSClient) SendError(err models.WsError) error {
 }
 
 // ServeWS 处理 WebSocket 升级请求。
-func ServeWS(sessionMgr session.Manager, orch orchestrator.Orchestrator, cfg *config.Config, tokenMgr *auth.TokenManager) gin.HandlerFunc {
+func ServeWS(sessionMgr session.Manager, orch orchestrator.Orchestrator, cfg *config.Config, tokenMgr *auth.TokenManager, scenarioRepo store.UserScenarioRepository) gin.HandlerFunc {
 	upgrader := newUpgrader(cfg)
 	heartbeatInterval := time.Duration(cfg.Server.HeartbeatInterval) * time.Second
 	heartbeatTimeout := time.Duration(cfg.Server.HeartbeatTimeout) * time.Second
 	version := cfg.App.Version
 
 	return func(c *gin.Context) {
-		serveWS(c, sessionMgr, orch, upgrader, heartbeatInterval, heartbeatTimeout, version, tokenMgr)
+		serveWS(c, sessionMgr, orch, upgrader, heartbeatInterval, heartbeatTimeout, version, tokenMgr, scenarioRepo)
 	}
 }
 
 func serveWS(c *gin.Context, sessionMgr session.Manager, orch orchestrator.Orchestrator,
-	upgrader websocket.Upgrader, heartbeatInterval, heartbeatTimeout time.Duration, version string, tokenMgr *auth.TokenManager) {
+	upgrader websocket.Upgrader, heartbeatInterval, heartbeatTimeout time.Duration, version string, tokenMgr *auth.TokenManager, scenarioRepo store.UserScenarioRepository) {
 
 	// --- JWT 认证（upgrade 前完成，失败直接返回 HTTP 错误） ---
 	token := c.Query("token")
@@ -289,7 +290,21 @@ func serveWS(c *gin.Context, sessionMgr session.Manager, orch orchestrator.Orche
 			if scenarioID != "" && scenarioID != "free_chat" {
 				sess, err := client.sessionMgr.Get(context.Background(), sessionID)
 				if err == nil && sess != nil {
-					greeting := llm.GetScenarioGreeting(scenarioID, sess.Config.Language)
+					// 加载用户自建情景
+					var customGreetings map[string]string
+					if sess.UserID != "" && scenarioRepo != nil {
+						scenarios, err := scenarioRepo.FindByUserID(context.Background(), sess.UserID)
+						if err == nil && len(scenarios) > 0 {
+							customGreetings = make(map[string]string, len(scenarios))
+							for _, s := range scenarios {
+								if s.Greeting != "" {
+									customGreetings[s.ID] = s.Greeting
+								}
+							}
+						}
+					}
+
+					greeting := llm.GetScenarioGreeting(scenarioID, sess.Config.Language, customGreetings)
 					if greeting != "" {
 						// 发送首句作为 AI 消息
 						_ = client.SendJSON(models.WsLLMChunk{

backend/migrations/004_user_scenarios.down.sql

@@ -0,0 +1,6 @@
+-- 004_user_scenarios.down.sql
+-- 回滚用户自建情景表
+
+DROP INDEX IF EXISTS idx_user_scenarios_created_at;
+DROP INDEX IF EXISTS idx_user_scenarios_user_id;
+DROP TABLE IF EXISTS user_scenarios;

backend/migrations/004_user_scenarios.up.sql

@@ -0,0 +1,36 @@
+-- 004_user_scenarios.up.sql
+-- 用户自建情景表
+
+CREATE TABLE user_scenarios (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    name VARCHAR(50) NOT NULL,
+    icon VARCHAR(10) DEFAULT '✨',
+    description VARCHAR(100) NOT NULL,
+    prompt TEXT NOT NULL,
+    greeting VARCHAR(200),
+    language VARCHAR(10) DEFAULT 'zh-CN',
+    created_at TIMESTAMP NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMP NOT NULL DEFAULT NOW(),
+
+    CONSTRAINT unique_user_scenario UNIQUE(user_id, name),
+    CONSTRAINT check_name_length CHECK (char_length(name) >= 2 AND char_length(name) <= 50),
+    CONSTRAINT check_description_length CHECK (char_length(description) >= 5 AND char_length(description) <= 100),
+    CONSTRAINT check_prompt_length CHECK (char_length(prompt) >= 50 AND char_length(prompt) <= 2000)
+);
+
+-- 为用户 ID 创建索引，加速查询
+CREATE INDEX idx_user_scenarios_user_id ON user_scenarios(user_id);
+
+-- 为创建时间创建索引，用于排序
+CREATE INDEX idx_user_scenarios_created_at ON user_scenarios(created_at DESC);
+
+COMMENT ON TABLE user_scenarios IS '用户自建情景表';
+COMMENT ON COLUMN user_scenarios.id IS '情景唯一标识';
+COMMENT ON COLUMN user_scenarios.user_id IS '所属用户 ID，外键关联 users 表';
+COMMENT ON COLUMN user_scenarios.name IS '情景名称，如"创意写作导师"';
+COMMENT ON COLUMN user_scenarios.icon IS 'Emoji 图标，如"🎨"';
+COMMENT ON COLUMN user_scenarios.description IS '简短描述，显示在情景卡片上';
+COMMENT ON COLUMN user_scenarios.prompt IS '角色 System Prompt，定义 AI 行为';
+COMMENT ON COLUMN user_scenarios.greeting IS '首句引导，可选';
+COMMENT ON COLUMN user_scenarios.language IS '默认语言，如 zh-CN、en-US';