Redact password from DatabaseSessionService engine-creation errors

[herdiyana256]

DatabaseSessionService.init includes the database URL in the ValueError it raises when engine creation fails. There are three such messages: one for an invalid URL argument (ArgumentError), one for a missing driver module (ImportError), and a generic one for any other failure. Each interpolated the raw db_url directly into the message text.

A SQLAlchemy URL for a networked backend carries the password inline, for example postgresql+asyncpg://user:password@host/db. As a result, any of these failures surfaces the database password verbatim in the exception and in any logs that record it. The most common trigger is entirely benign: configuring a Postgres or MySQL URL without having installed the corresponding async driver raises the ImportError branch, which then prints the full URL including the password. The underlying SQLAlchemy exceptions in these paths do not contain the password, so the disclosure is introduced solely by these messages.

This change renders the URL with hide_password=True before including it in the messages, so the password is replaced with *** while the dialect, host, and database remain visible for debugging. When the URL cannot be parsed at all, it falls back to a redacted placeholder rather than echoing the raw string.

Verified against the current published class: before the change, instantiating DatabaseSessionService with a password-bearing Postgres URL whose driver is not installed raises ... 'postgresql+asyncpg://admin:SUPER_SECRET_PW@db.internal:5432/prod' with the password in clear text; after the change the same call reports ...admin:***@db.internal:5432/prod and the password no longer appears in the error for any of the three branches.

[rohityan]

Hi @herdiyana256 , Thank you for your contribution! We appreciate you taking the time to submit this pull request. Can you please add a unit test verifying that _redact_db_url masks passwords and that DatabaseSessionService.__init__ exceptions do not expose credentials.
Also can you please fix the failing ci tests.

[herdiyana256]

Thanks @rohityan! Added unit tests in tests/unittests/sessions/test_session_service.py:

• test_redact_db_url_masks_embedded_password and test_redact_db_url_falls_back_to_placeholder_for_unparsable_url cover _redact_db_url directly — the password is stripped while host/database/user are kept, and unparsable URLs fall back to [redacted].
• test_database_session_service_init_error_does_not_leak_password (parametrized over ArgumentError, ImportError, and a generic error) asserts the ValueError raised from DatabaseSessionService.__init__ never contains the URL password, while still keeping the host so the message stays actionable.

All pass locally (pytest tests/unittests/sessions/test_session_service.py), and the branch is rebased on latest main with CLA/checks green. PTAL.