refactor: organize type definitions into dedicated db/types/ directory

- Move type files to src/db/types/: currency_type, listing_id, user_id, money_amount, telegram_user_id
- Create types/mod.rs with proper re-exports for all type modules
- Update db/mod.rs to import from new types module instead of individual files
- All tests pass - no functionality changes
- Improves code organization by clearly separating types, DAOs, and models

Cargo.toml

@@ -10,6 +10,7 @@ sqlx = { version = "0.8.6", features = [
     "runtime-tokio-rustls",
     "sqlite",
     "chrono",
+    "macros",
     "rust_decimal",
 ] }
 rust_decimal = { version = "1.33", features = ["serde"] }

src/db/mod.rs

@@ -1,16 +1,8 @@
-pub mod currency_type;
 pub mod dao;
-pub mod listing_id;
 pub mod models;
-pub mod money_amount;
-pub mod telegram_user_id;
-pub mod user_id;
+pub mod types;
 
-// Re-export all models for easy access
-pub use currency_type::*;
+// Re-export all modules for easy access
 pub use dao::*;
-pub use listing_id::*;
 pub use models::*;
-pub use money_amount::*;
-pub use telegram_user_id::*;
-pub use user_id::*;
+pub use types::*;

src/db/types/mod.rs

@@ -0,0 +1,12 @@
+pub mod currency_type;
+pub mod listing_id;
+pub mod money_amount;
+pub mod telegram_user_id;
+pub mod user_id;
+
+// Re-export all types for easy access
+pub use currency_type::*;
+pub use listing_id::*;
+pub use money_amount::*;
+pub use telegram_user_id::*;
+pub use user_id::*;