🔧 Fix 1000+ warnings: Remove dead code and apply cargo fix

- Eliminated dead code methods (get_connection_state, etc.)
- Fixed unused variable warnings by prefixing with underscore
- Applied cargo fix to all major crates
- Reduced warnings from 6442 to ~5295
- Fixed event_sender variable warnings across codebase
- Removed truly unused methods and constants

Remaining warnings are primarily:
- Documentation (missing_docs) - ~4700 warnings
- Minor unused fields/methods - ~500 warnings
- These are non-critical and can be addressed incrementally

common/src/lib.rs

@@ -45,8 +45,6 @@ pub use error::{CommonError, CommonResult, ErrorCategory, ErrorSeverity, RetrySt
 mod sqlx_test;
 
 #[cfg(feature = "database")]
-
-
 pub mod prelude {
     //! Common types and utilities for Foxhunt services