Refactor error handling in IAM and CMS crates

- Introduced `RepositoryError` and `ServiceError` enums in both IAM and CMS domains for better error management.
- Updated domain traits and services to return specific error types instead of `anyhow::Result`.
- Enhanced session and OAuth repository implementations to handle errors more explicitly.
- Refactored session service methods to return `Result<T, ServiceError>` for improved error handling.
- Updated HTTP handlers to utilize the new error types.
- Modified password hashing functions to run in a blocking context using `tokio::task::spawn_blocking`.
- Added tests for new error handling mechanisms and async password functions.

crates/zesdex-entities/src/domain/auth/session_lock.rs

@@ -15,6 +15,7 @@
 //! - `try_lock` — three-phase atomic acquire with stale-lock recovery
 //! - `unlock` / `Drop` — explicit and implicit release
 //! - `is_alive` — liveness check via `libc::kill` + `/proc` verification
+use std::convert::TryInto;
 use std::fs;
 use std::io::Write;
 use std::path::{Path, PathBuf};
@@ -117,7 +118,9 @@ impl SessionLock {
         // SAFETY: `libc::kill(pid, 0)` does not send a signal; it only checks
         // whether the process exists and the caller has permission to signal
         // it. The integer argument is a PID already validated by `try_lock`.
-        if unsafe { libc::kill(pid as i32, 0) != 0 } {
+        // PIDs on Linux fit in i32 (default pid_max ≈ 4 million).
+        let pid_signed: i32 = pid.try_into().unwrap_or(0);
+        if unsafe { libc::kill(pid_signed, 0) != 0 } {
             return false;
         }
         // Extra check: verify the PID belongs to a zesdex process via

crates/zesdex-entities/src/domain/common/provider.rs

@@ -330,7 +330,8 @@ impl SseParser {
                                                     );
                                                     0
                                                 },
-                                            ) as usize;
+                                            );
+                                        let index = usize::try_from(index).unwrap_or(0);
                                         let id = tc
                                             .get("id")
                                             .and_then(|i| i.as_str())

crates/zesdex-entities/src/lib.rs

@@ -1,10 +1,3 @@
-#![allow(
-    clippy::cast_possible_truncation,
-    clippy::cast_sign_loss,
-    clippy::cast_precision_loss,
-    clippy::cast_possible_wrap
-)]
-
 //! Domain entity types for the Zesdex application.
 //!
 //! This crate contains ALL domain entity types as pure data structures