feat(Notification & membership route)

database/migrations/2025_10_20_111428_create_memberships_table.php

@@ -16,7 +16,7 @@ return new class extends Migration
             $table->foreignId('member_id')->constrained('members')->onDelete('cascade');
             $table->foreignId('admin_id')->nullable()->constrained('users')->onDelete('set null');
             $table->foreignId('package_id')->constrained('packages')->onDelete('cascade');
-            $table->date('start_date');
+            $table->date('start_date')->nullable();
             $table->date('end_date')->nullable();
             $table->enum('status', ['active', 'expired', 'pending'])->default('pending');
             $table->decimal('amount', 10, 2)->default(0);