feat: add Number Connect game with ABC spatial optimization and auto-pagination

pkg/learnnumber/tool.go

@@ -29,9 +29,24 @@ func (t *learnNumberTool) Init() error {
 
 func (t *learnNumberTool) RegisterRoutes(r *gin.RouterGroup) {
 	r.POST("/counting", t.handleCounting)
+	r.POST("/writing", t.handleWriting)
 	r.GET("/categories", t.handleCategories)
 }
 
+func (t *learnNumberTool) handleWriting(c *gin.Context) {
+	var req logic.WritingRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+	pdfBytes, err := logic.GenerateWritingPDF(req)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.Data(http.StatusOK, "application/pdf", pdfBytes)
+}
+
 func (t *learnNumberTool) handleCategories(c *gin.Context) {
 	// 返回分类信息供前端预览
 	c.JSON(http.StatusOK, data.IconCategories)