Rename the import package app to fluksio

A wheel whose top-level module is `app` collides with anything else in a
user's venv, so the package that is about to be published takes the name
it is published under. Only the Python package moves; the repo, the
Docker WORKDIR and the compose project keep theirs.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

backend/scripts/bench_startup.py

@@ -31,7 +31,7 @@ from typing import Any
 
 sys.path.insert(0, str(__import__("pathlib").Path(__file__).resolve().parents[1]))
 
-from app.core.config import settings  # noqa: E402
+from fluksio.core.config import settings  # noqa: E402
 
 log = logging.getLogger("bench")