style: Apply rustfmt with stable-only config

- Fixed rustfmt.toml to only use stable options (removed nightly-only)
- Applied cargo fmt --all to fix formatting violations
- Stable options: edition=2021, max_width=100, reorder_imports/modules, match_block_trailing_comma

crates/pm-core/src/lib.rs

@@ -1,20 +1,19 @@
+pub mod audit;
 pub mod config;
 pub mod db;
 pub mod error;
 pub mod logging;
 pub mod models;
-pub mod audit;
 pub mod request_id;
 
 // Re-export commonly used types
-pub use error::{AppError, ErrorResponse};
 pub use config::AppConfig;
+pub use error::{AppError, ErrorResponse};
 pub use models::{
-    Host, HostSummary, HostHealthStatus, CreateHostRequest,
-    Group, CreateGroupRequest, UpdateGroupRequest,
-    User, UserRole as DbUserRole, AuthProvider, CreateUserRequest, UpdateUserRequest,
-    DiscoveryResult, DiscoveryCidrRequest, RegisterDiscoveredRequest,
+    AuthProvider, CreateGroupRequest, CreateHostRequest, CreateUserRequest, DiscoveryCidrRequest,
+    DiscoveryResult, Group, Host, HostHealthStatus, HostSummary, RegisterDiscoveredRequest,
+    UpdateGroupRequest, UpdateUserRequest, User, UserRole as DbUserRole,
 };
 
 // Re-export audit integrity types
-pub use audit::{verify_integrity, IntegrityResult, IntegrityError};
+pub use audit::{verify_integrity, IntegrityError, IntegrityResult};