fix(auth): propagate error when token directory cannot be created (#542)

* fix(auth): propagate errors when token directory creation/permissions fail

Previously, failures to create the token directory or set its permissions
were silently ignored using 'let _ = ...'. This could lead to confusing
errors later or security issues if permissions were left insecure.

Now properly propagates errors from:
- tokio::fs::create_dir_all()
- std::fs::set_permissions() (on Unix)

Also sanitizes the path in error messages to prevent terminal escape
sequence injection, aligned with codebase security practices.

* fix(auth): use spawn_blocking for set_permissions to avoid blocking async runtime

Following the reviewer suggestion, std::fs::set_permissions is now executed
via tokio::task::spawn_blocking to avoid potentially blocking the async
runtime thread, which can cause performance issues or deadlocks under load.

* fix(auth): use tokio::fs::set_permissions instead of spawn_blocking

Simplifies the code by using Tokio's native async set_permissions,
removing the need for manual thread spawning.

.changeset/fix-token-dir-error-propagation.md

@@ -0,0 +1,5 @@
+---
+"gws": patch
+---
+
+Fix auth error propagation: properly propagate errors when token directory creation or permission setting fails, instead of silently ignoring them

src/token_storage.rs

@@ -82,11 +82,25 @@ impl EncryptedTokenStorage {
         let encrypted = crate::credential_store::encrypt(json.as_bytes())?;
 
         if let Some(parent) = self.file_path.parent() {
-            let _ = tokio::fs::create_dir_all(parent).await;
+            tokio::fs::create_dir_all(parent).await.map_err(|e| {
+                anyhow::anyhow!(
+                    "Failed to create token directory '{}': {}",
+                    sanitize_for_terminal(&parent.display().to_string()),
+                    e
+                )
+            })?;
             #[cfg(unix)]
             {
                 use std::os::unix::fs::PermissionsExt;
-                let _ = std::fs::set_permissions(parent, std::fs::Permissions::from_mode(0o700));
+                tokio::fs::set_permissions(parent, std::fs::Permissions::from_mode(0o700))
+                    .await
+                    .map_err(|e| {
+                        anyhow::anyhow!(
+                            "Failed to set permissions on token directory '{}': {}",
+                            sanitize_for_terminal(&parent.display().to_string()),
+                            e
+                        )
+                    })?;
             }
         }