Refactor and clean up code across multiple modules

- Simplified token type assignment in OAuth service.
- Removed unused session_lock module and re-exported Session from zesdex_entities.
- Cleaned up session entity by removing unnecessary comments and code.
- Consolidated session handling in HTTP handlers for better readability.
- Improved formatting and readability in OAuth repository tests.
- Enhanced session lock repository with clearer match statements.
- Streamlined session repository error handling.
- Refined RNG tests for better clarity.
- Adjusted module visibility and organization in lib.rs.
- Updated IPC client and connection code for better error handling and clarity.
- Improved frame handling in IPC for better readability.
- Organized module imports and added test utilities for IPC.
- Enhanced database connection error handling.
- Simplified JWT token creation error handling.
- Improved password verification error handling.
- Cleaned up state management code for better readability.
- Refactored middleware for session authentication and rate limiting.
- Simplified clipboard utility for better error handling.
- Enhanced logging initialization for better error reporting.
- Improved pagination utility with clearer method annotations.
- Cleaned up sanitization functions for filenames and paths.
- Enhanced slug generation functions for better clarity and usability.

crates/zesdex-backend/src/tool/shell.rs

@@ -64,11 +64,7 @@ impl Tool for Bash {
     /// Return: exit-code + elapsed-seconds summary line (plus captured output) for
     /// foreground runs, or the job ID for background runs.
     fn run(&self, _ctx: &ToolCtx, args: &Value) -> Result<String> {
-        let cmd = args
-            .get("command")
-            .and_then(|v| v.as_str())
-            .ok_or_else(|| anyhow!("missing required argument: command"))?
-            .to_string();
+        let cmd = crate::tool::arg_str(args, "command")?;
         let timeout_ms = args
             .get("timeout")
             .and_then(serde_json::Value::as_u64)