refactor: [#255] move database module into config/core

- Convert core.rs into folder module (config/core/)
- Move database module into config/core/database/
- Update imports to reflect new structure
- Database types now exported through config module hierarchy
- Improves logical grouping (database is part of core config)
- All 1582 tests passing
- All linters passing

Author: josecelano

src/domain/tracker/database/mod.rs …main/tracker/config/core/database/mod.rssrc/domain/tracker/database/mod.rs renamed to src/domain/tracker/config/core/database/mod.rs src/domain/tracker/database/mod.rs renamed to src/domain/tracker/config/core/database/mod.rs

@@ -2,7 +2,9 @@
 
 use serde::{Deserialize, Serialize};
 
-use crate::domain::tracker::DatabaseConfig;
+mod database;
+
+pub use database::{DatabaseConfig, MysqlConfig, SqliteConfig};
 
 /// Core tracker configuration options
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
@@ -17,7 +19,6 @@ pub struct TrackerCoreConfig {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::domain::tracker::{DatabaseConfig, SqliteConfig};
 
     #[test]
     fn it_should_create_core_config() {

src/domain/tracker/database/mysql.rs …in/tracker/config/core/database/mysql.rssrc/domain/tracker/database/mysql.rs renamed to src/domain/tracker/config/core/database/mysql.rs src/domain/tracker/database/mysql.rs renamed to src/domain/tracker/config/core/database/mysql.rs

@@ -13,14 +13,12 @@ mod http;
 mod http_api;
 mod udp;
 
-pub use core::TrackerCoreConfig;
+pub use core::{DatabaseConfig, MysqlConfig, SqliteConfig, TrackerCoreConfig};
 pub use health_check_api::HealthCheckApiConfig;
 pub use http::HttpTrackerConfig;
 pub use http_api::HttpApiConfig;
 pub use udp::UdpTrackerConfig;
 
-use super::{DatabaseConfig, SqliteConfig};
-
 /// Tracker deployment configuration
 ///
 /// This structure mirrors the real tracker configuration but only includes

src/domain/tracker/database/sqlite.rs …n/tracker/config/core/database/sqlite.rssrc/domain/tracker/database/sqlite.rs renamed to src/domain/tracker/config/core/database/sqlite.rs src/domain/tracker/database/sqlite.rs renamed to src/domain/tracker/config/core/database/sqlite.rs

@@ -5,8 +5,7 @@
 //!
 //! # Module Structure
 //!
-//! - `config` - Main `TrackerConfig` and component configurations
-//! - `database` - Database configuration (`SQLite`, `MySQL`)
+//! - `config` - Main `TrackerConfig` and component configurations (includes database)
 //!
 //! # Layer Separation
 //!
@@ -46,10 +45,8 @@
 //! ```
 
 mod config;
-mod database;
 
 pub use config::{
-    HealthCheckApiConfig, HttpApiConfig, HttpTrackerConfig, TrackerConfig, TrackerCoreConfig,
-    UdpTrackerConfig,
+    DatabaseConfig, HealthCheckApiConfig, HttpApiConfig, HttpTrackerConfig, MysqlConfig,
+    SqliteConfig, TrackerConfig, TrackerCoreConfig, UdpTrackerConfig,
 };
-pub use database::{DatabaseConfig, MysqlConfig, SqliteConfig};