webui: Make some user preferences configurable

This extends 09f0237560.

- Extend user_pref with configurable profile fields and automatic migration defaults
- Move user info responses to read from user_pref instead of hardcoded values
- Add admin profile page for editing UI values after login

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

internal/handler/user/userinfo.go

@@ -2,7 +2,6 @@ package user
 
 import (
 	"honoka-chan/internal/middleware"
-	usermodel "honoka-chan/internal/model/user"
 	"honoka-chan/internal/router"
 	userschema "honoka-chan/internal/schema/user"
 	"honoka-chan/internal/session"
@@ -15,12 +14,6 @@ func userInfo(ctx *gin.Context) {
 	ss := session.Get(ctx)
 	defer ss.Finalize()
 
-	pref := usermodel.UserPref{}
-	_, err := ss.UserEng.Table("user_pref").Where("user_id = ?", ss.UserID).Get(&pref)
-	if ss.CheckErr(err) {
-		return
-	}
-
 	userResp := userschema.UserInfoResp{
 		ResponseData: userschema.UserInfoData{
 			User: ss.GetUserInfo(),