前端极简黑白重设计,并纳入客户端注册、站点设置与后台相关改动

- storefront 全站改为极简黑白配色:直角、细线分隔、卡片 hover 浅底、深色模式(跟随系统+手动切换)
- 抽出 storefront/partials/card 复用卡片
- 一并提交此前暂存的客户端注册 API、站点设置、后台页面与测试

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

routes/api.php

@@ -1,9 +1,16 @@
 <?php
 
 use Illuminate\Support\Facades\Route;
+use App\Http\Controllers\Api\ClientController;
 use App\Http\Controllers\Api\RepoController;
 use App\Http\Controllers\Api\CategoryController;
 
+Route::prefix('v1/client')->group(function () {
+    Route::post('/register', [ClientController::class, 'register']);
+    Route::post('/heartbeat', [ClientController::class, 'heartbeat']);
+    Route::get('/status', [ClientController::class, 'status']);
+});
+
 Route::prefix('v1/repo')->group(function () {
     Route::get('/index', [RepoController::class, 'index']);
     Route::get('/packages/{type}/{slug}', [RepoController::class, 'detail'])