feat: enhance project and scenario management with role-based access control

- Implemented role-based access control for project and scenario routes.
- Added authorization checks to ensure users have appropriate roles for viewing and managing projects and scenarios.
- Introduced utility functions for ensuring project and scenario access based on user roles.
- Refactored project and scenario routes to utilize new authorization helpers.
- Created initial data seeding script to set up default roles and an admin user.
- Added tests for authorization helpers and initial data seeding functionality.
- Updated exception handling to include authorization errors.

.env.example

@@ -9,6 +9,3 @@ DATABASE_PASSWORD=<password>
 DATABASE_NAME=calminer
 # Optional: set a schema (comma-separated for multiple entries)
 # DATABASE_SCHEMA=public
-
-# Legacy fallback (still supported, but granular settings are preferred)
-# DATABASE_URL=postgresql://<user>:<password>@localhost:5432/calminer