feat: 添加 AI 记账功能，包括 API 处理器和核心服务逻辑。

internal/handler/ai_handler.go

@@ -1,6 +1,7 @@
 package handler
 
 import (
+	"encoding/json"
 	"net/http"
 
 	"accounting-app/internal/service"
@@ -26,6 +27,11 @@ type ChatRequest struct {
 	Message   string `json:"message" binding:"required"`
 }
 
+// InsightRequest represents an insight generation request
+type InsightRequest struct {
+	ContextData map[string]interface{} `json:"context_data" binding:"required"`
+}
+
 // TranscribeRequest represents a transcription request
 type TranscribeRequest struct {
 	// Audio file is sent as multipart form data
@@ -43,6 +49,7 @@ func (h *AIHandler) RegisterRoutes(rg *gin.RouterGroup) {
 		ai.POST("/chat", h.Chat)
 		ai.POST("/transcribe", h.Transcribe)
 		ai.POST("/confirm", h.Confirm)
+		ai.POST("/insight", h.Insight)
 	}
 }
 
@@ -80,11 +87,53 @@ func (h *AIHandler) Chat(c *gin.Context) {
 	})
 }
 
+// Insight handles daily insight generation
+// POST /api/v1/ai/insight
+func (h *AIHandler) Insight(c *gin.Context) {
+	var req InsightRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{
+			"success": false,
+			"error":   "Invalid request: " + err.Error(),
+		})
+		return
+	}
+
+	userID := uint(1)
+	if id, exists := c.Get("user_id"); exists {
+		userID = id.(uint)
+	}
+
+	insightJSON, err := h.aiService.GenerateDailyInsight(c.Request.Context(), userID, req.ContextData)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{
+			"success": false,
+			"error":   "Failed to generate insight: " + err.Error(),
+		})
+		return
+	}
+
+	// Try to parse the JSON string from LLM to ensure structure
+	var result map[string]interface{}
+	if err := json.Unmarshal([]byte(insightJSON), &result); err != nil {
+		// Fallback if LLM output isn't valid JSON (rare with correct prompt)
+		result = map[string]interface{}{
+			"spending": insightJSON,
+			"budget":   "暂无建议",
+		}
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"success": true,
+		"data":    result,
+	})
+}
+
 // Transcribe handles audio transcription
 // POST /api/v1/ai/transcribe
 // Requirements: 12.2, 12.6
 func (h *AIHandler) Transcribe(c *gin.Context) {
-	// Get audio file from form
+	// ... existing body ...
 	file, header, err := c.Request.FormFile("audio")
 	if err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{