refactor: enhance permission handling and introduce new Permission and Policy classes

- Updated the `Guard` class to improve permission checking by utilizing the new `Permission` class.
- Refactored tests in `authorize.spec.ts` to use `Permission` instances instead of strings for better type safety.
- Introduced a new `permissions.spec.ts` file to test the functionality of the `Permission` and `Policy` classes.
- Enhanced the `recursivelyReplacePlaceholders` utility function to support various object structures and types.
- Updated middleware and controller files to align with the new permission handling structure.

app/src/modules/ModuleHelper.ts

@@ -115,7 +115,7 @@ export class ModuleHelper {
    }
 
    async throwUnlessGranted(
-      permission: Permission | string,
+      permission: Permission,
       c: { context: ModuleBuildContextMcpContext; raw?: unknown },
    ) {
       invariant(c.context.app, "app is not available in mcp context");