refactor: migrate role handling from tiers to roles module

- Removed the deprecated tiers.ts file and migrated all related functionality to roles/index.js.
- Updated tests and tools to reflect the new role structure, replacing references to "dev", "qa", and "architect" with "developer", "tester", and "architect".
- Adjusted workflow configurations and state management to accommodate the new role naming conventions.
- Enhanced project registration and health check tools to support dynamic role handling.
- Updated task creation, update, and completion processes to align with the new role definitions.
- Improved documentation and comments to clarify role responsibilities and usage.

lib/roles/index.ts

@@ -13,7 +13,11 @@ export {
   isValidRole,
   getRole,
   requireRole,
+  // Role aliases
+  ROLE_ALIASES,
+  canonicalRole,
   // Level aliases
+  LEVEL_ALIASES,
   canonicalLevel,
   // Levels
   getLevelsForRole,