feat: replace Redis with PostgreSQL for caching, rate limiting, SMS codes, and token blacklist

- Add 4 PG entities: VerificationCode, RateLimitEntry, TokenBlacklistEntry, CacheEntry
- Add 4 services: VerificationService, RateLimitService, TokenBlacklistService, CacheService
- Add CleanupBackgroundService for periodic expired data cleanup
- Add MigrationHelper for safe schema migration without data loss
- Update AuthController: real SMS code generation, rate limiting, logout endpoint with JWT blacklist
- Update JwtProvider: add JTI claim for token revocation
- Update Program.cs: register new services, JWT blacklist validation, DB migration
- Remove StackExchange.Redis NuGet package and all Redis config references
- Update start-dev.bat: 6→5 services, remove Redis startup
- Update docs: remove Redis references from all documentation
- Fix: logout button spacing on profile page
- Fix: .gitignore data/→/data/ to not ignore Infrastructure/Data/

backend/技术文档-后端.md

@@ -43,7 +43,6 @@
 | **SignalR** | 微软的实时通信框架 | 实现医生和患者之间的实时聊天 |
 | **Swagger** | API 文档工具 | 自动生成 API 文档页面，可以直接在浏览器里测试接口 |
 | **MinIO** | S3 兼容的对象存储 | 存储图片（报告照片、头像等） |
-| **Redis** | 内存缓存数据库 | 缓存常用数据，加速访问 |
 
 ### 1.3 项目文件结构
 
@@ -385,7 +384,7 @@ DTO = Data Transfer Object。用于前后端之间传输数据，而不是直接
 
 | 文件 | 内容 |
 |------|------|
-| `appsettings.json` | PostgreSQL 连接串、JWT 密钥/签发者、Redis 连接、MinIO 连接 |
+| `appsettings.json` | PostgreSQL 连接串、JWT 密钥/签发者、MinIO 连接 |
 | `appsettings.Development.json` | 开发环境覆盖配置 |
 | `Properties/launchSettings.json` | 启动配置：端口 5000，Development 环境，自动开 Swagger |