继续收口暗色弹窗底部动作区

新增 PlatformDarkModalFooter 统一 dark modal footer 的布局壳
接入 NPC 弹窗、选择定制弹窗、任务更新弹层与物品详情 footer
补充组件级与弹窗集成测试并更新收口计划和共享决策记录

src/components/SelectionCustomizationModals.tsx

@@ -5,6 +5,7 @@ import type {
   CustomWorldGenerationMode,
 } from '../types';
 import { PlatformActionButton } from './common/PlatformActionButton';
+import { PlatformDarkModalFooter } from './common/PlatformDarkModalFooter';
 import { PlatformModalCloseButton } from './common/PlatformModalCloseButton';
 import { PlatformProgressBar } from './common/PlatformProgressBar';
 import { PlatformStatusMessage } from './common/PlatformStatusMessage';
@@ -46,9 +47,13 @@ function SelectionModal({
           {children}
         </div>
         {footer ? (
-          <div className="flex flex-wrap items-center justify-end gap-3 border-t border-white/10 px-5 py-4">
+          <PlatformDarkModalFooter
+            wrap
+            padding="roomy"
+            data-testid="selection-modal-footer"
+          >
             {footer}
-          </div>
+          </PlatformDarkModalFooter>
         ) : null}
       </div>
     </div>