fix: auto-apply DB schema on fresh install and fix admin registration (#81)

- Auto-apply schema.sql when database tables don't exist (embedded in binary)
- Handle missing tables gracefully during admin registration (treat as fresh install)
- Fix docker-compose depends_on to wait for postgres healthcheck
- Rename personal folder from 'Mi Carpeta' to 'My Folder' with backward compat
- Translate remaining Spanish messages to English

src/infrastructure/repositories/pg/user_pg_repository.rs

@@ -54,7 +54,7 @@ impl UserPgRepository {
 impl UserRepository for UserPgRepository {
     /// Creates a new user using a transaction
     async fn create_user(&self, user: User) -> UserRepositoryResult<User> {
-        // Creamos una copia del usuario para el closure
+        // Create a copy of the user for the closure
         let user_clone = user.clone();
         
         with_transaction(