fix: add MySQL database and fix deployment issues

## Changes

### Database Integration
- Add MySQL 8.0 service to docker-compose.yml
- Configure DATABASE_URL environment variable for server
- Add health check for MySQL service
- Create mysql_data volume for data persistence

### Dockerfile Improvements
- Generate Prisma Client in builder stage
- Copy Prisma Client from correct pnpm workspace location
- Ensure Prisma Client is available in production container

### Client-Mobile Fixes
- Remove deprecated StampDock.vue component
- Fix voting store API usage in VotingPage.vue
- Add type assertion for userTickets in connection.ts
- Add remark property to AwardConfig interface in voting.ts

## Testing
- All containers start successfully
- Database connection established
- Redis connection working
- 94 participants restored from Redis
- Vote data synced (20 votes)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

packages/client-mobile/src/views/VotingPage.vue

@@ -37,7 +37,7 @@ onMounted(async () => {
     <header class="page-header">
       <h1 class="page-title">节目投票</h1>
       <p class="page-subtitle">
-        已使用 {{ votingStore.usedTickets.length }}/7 枚印章
+        已使用 {{ votingStore.usedTicketCount }}/{{ votingStore.totalTicketCount }} 枚印章
       </p>
       <ConnectionStatus />
     </header>