Refactor Alembic upgrade command in Jenkinsfile for improved execution

- Updated the Alembic upgrade command to use a Python script for execution, addressing issues with configuration handling in Docker.
- Enhanced comments to clarify the purpose of the changes and their implications for E2E testing.

Jenkinsfile

@@ -284,9 +284,8 @@ pipeline {
             e2e_compose_fail_logs
             exit 1
           fi
-          # Binario /usr/local/bin/alembic: sin python3 -m (el -c rompe; log con -c = build sin el último commit)
-          # --config=/ruta evita un token que empiece con - (algunos compose run lo mezclan con sus flags)
-          if ! e2e_compose run --rm --no-deps --entrypoint /usr/local/bin/alembic backend --config=/app/alembic.ini upgrade head; then
+          # e2e_alembic_upgrade.py: carga /app/alembic.ini en la API; la CLI a veces queda con config vacío bajo compose (No 'script_location')
+          if ! e2e_compose run --rm --no-deps --entrypoint /usr/local/bin/python3 backend /app/e2e_alembic_upgrade.py; then
             echo "ERROR: falló alembic upgrade head (job previo al stack completo)"
             e2e_compose_fail_logs
             exit 1

backend/e2e_alembic_upgrade.py

@@ -0,0 +1,38 @@
+"""
+E2E/Jenkins: aplica migraciones sin la CLI de Alembic.
+
+docker compose run … alembic --config=… a veces deja un Config vacío (No 'script_location');
+aquí se carga explícitamente /app/alembic.ini y se llama a command.upgrade().
+"""
+from __future__ import annotations
+
+import os
+import sys
+from pathlib import Path
+
+
+def main() -> int:
+    root = Path("/app")
+    if not root.is_dir():
+        print("ERROR: /app no es un directorio (volumen backend).", file=sys.stderr)
+        return 1
+    os.chdir(root)
+    sys.path.insert(0, str(root))
+
+    ini = root / "alembic.ini"
+    if not ini.is_file():
+        print(
+            f"ERROR: {ini} no existe. Comprueba el bind ./backend:./app en el agente.",
+            file=sys.stderr,
+        )
+        return 1
+
+    from alembic.config import Config
+    from alembic import command
+
+    command.upgrade(Config(str(ini)), "head")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())