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>

static/templates/admin/profile.html

@@ -15,6 +15,22 @@
             flex-wrap: wrap;
         }
 
+        .profile-birth-row {
+            display: flex;
+            gap: 10px;
+            align-items: center;
+        }
+
+        .profile-birth-field {
+            flex: 1 1 0;
+            min-width: 0;
+        }
+
+        .profile-birth-sep {
+            color: #666;
+            white-space: nowrap;
+        }
+
         .profile-action-row .layui-btn+.layui-btn {
             margin-left: 0;
         }
@@ -24,6 +40,10 @@
                 flex-direction: column;
                 align-items: stretch;
             }
+
+            .profile-birth-row {
+                gap: 8px;
+            }
         }
     </style>
 </head>
@@ -93,6 +113,24 @@
                             <div class="layui-form-mid layui-word-aux">填 0 时按体力上限返回给客户端。</div>
                         </div>
                     </div>
+                    <div class="layui-form-item">
+                        <label class="layui-form-label">生日</label>
+                        <div class="layui-input-block">
+                            <div class="profile-birth-row">
+                                <div class="profile-birth-field">
+                                    <input type="number" name="birth_month" min="1" max="12" required lay-verify="required"
+                                        autocomplete="off" class="layui-input" value="{{ .pref.EffectiveBirthMonth }}">
+                                </div>
+                                <div class="profile-birth-sep">月</div>
+                                <div class="profile-birth-field">
+                                    <input type="number" name="birth_day" min="1" max="31" required lay-verify="required"
+                                        autocomplete="off" class="layui-input" value="{{ .pref.EffectiveBirthDay }}">
+                                </div>
+                                <div class="profile-birth-sep">日</div>
+                            </div>
+                            <div class="layui-form-mid layui-word-aux">格式为 月 / 日，默认 10 / 18。</div>
+                        </div>
+                    </div>
                     <div class="layui-form-item">
                         <label class="layui-form-label">用户 ID</label>
                         <div class="layui-input-block">