Add support for database read replicas using the GORM dbresolver plugin. This allows for scaling read operations by distributing them across one or multiple replica nodes.
- Update `DatabaseConfig` to support single and multiple replica configurations.
- Add configuration options for replica connection pooling and selection policy.
- Integrate `dbresolver` in the database initialization process for PostgreSQL.
- Add helper methods to aggregate replica configurations.
- Add Google Wire for compile-time dependency injection
- Replace concrete service types with interfaces across handlers
- Remove global state (DB, cache) in favor of constructor injection
- Split monolithic files into focused modules:
- config: separate files for each config domain
- dto: converters split by domain (user, post, message, group)
- cache: separate metrics.go and redis_cache.go
- Introduce unified apperrors package with string-based error codes
- Add transaction support with context-aware repository methods
- Upgrade golang.org/x/crypto from 0.17.0 to 0.26.0
