webui: Add user birthday settings

- Store birth month and day in user_pref with default 10/18
- Migrate existing user_pref rows to fill missing birthday fields
- Expose birthday editing in the webui profile page
- Replace hardcoded birthday values in user info, top info, and product list responses
- Fix birthday month/day field alignment in the profile form

Signed-off-by: Sean Du <do4suki@gmail.com>

internal/handler/api/payment/payment.go

@@ -1,11 +1,15 @@
 package payment
 
-import "fmt"
+import (
+	"fmt"
 
-func PaymentApi(action string) (res any, err error) {
+	"github.com/gin-gonic/gin"
+)
+
+func PaymentApi(ctx *gin.Context, action string) (res any, err error) {
 	switch action {
 	case "productList":
-		res, err = productList()
+		res, err = productList(ctx)
 	default:
 		err = fmt.Errorf("unimplemented action: payment: %s", action)
 	}

internal/handler/api/payment/productlist.go

@@ -2,17 +2,22 @@ package payment
 
 import (
 	paymentapischema "honoka-chan/internal/schema/api/payment"
+	"honoka-chan/internal/session"
 	"time"
+
+	"github.com/gin-gonic/gin"
 )
 
-func productList() (res any, err error) {
+func productList(ctx *gin.Context) (res any, err error) {
+	ss := session.Get(ctx)
+
 	res = paymentapischema.ProductListResp{
 		Result: paymentapischema.ProductListData{
 			RestrictionInfo: paymentapischema.RestrictionInfo{
 				Restricted: false,
 			},
 			UnderAgeInfo: paymentapischema.UnderAgeInfo{
-				BirthSet:    false,
+				BirthSet:    ss.UserPref.HasBirthDate(),
 				HasLimit:    false,
 				LimitAmount: nil,
 				MonthUsed:   0,