Add comprehensive documentation and unit tests

Documentation:
- Add detailed README files for all services (auth, character, database, launcher, packet, utils, world)
- Create API documentation for the database service with detailed endpoint specifications
- Document database schema and relationships
- Add service architecture overviews and configuration instructions

Unit Tests:
- Implement comprehensive test suite for database repositories (user, character, session)
- Add gRPC service tests for database interactions
- Create tests for packet service components (bufferpool, connection, packets)
- Add utility service tests (health check, logging, load balancer, redis cache, service discovery)
- Implement auth service user tests
- Add character service tests

Code Structure:
- Reorganize test files into a more consistent structure
- Create a dedicated tests crate for integration testing
- Add test helpers and mock implementations for easier testing

character-service/Cargo.toml

@@ -12,7 +12,6 @@ tracing = "0.1"
 tracing-subscriber = { version = "0.3.19", features = ["env-filter", "chrono"] }
 tonic = "0.12.3"
 prost = "0.13.4"
-warp = "0.3.7"
 async-trait = "0.1.83"
 serde_json = "1.0.133"
 tonic-health = "0.12.3"