feat: Qobuz auth-token (user_id + token) login as a reliable alternative to email/password

Qobuz's email/password API login returns 401 even with valid credentials
(a known Qobuz limitation, unaffected by streamrip version). Add settings
fields for a Qobuz user ID + auth token (token stored encrypted); when both
are present StreamripClient uses use_auth_token=True, else falls back to
email/password.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

worker/tests/test_streamrip_auth.py

@@ -11,5 +11,12 @@ def test_hashed_password_is_md5_hex():
 
 
 def test_is_configured():
+    # email + password
     assert StreamripClient({"qobuz.email": "a@b.c", "qobuz.password": "p"}).is_configured() is True
+    # user_id + auth token (the reliable path)
+    assert StreamripClient({"qobuz.user_id": "123", "qobuz.auth_token": "tok"}).is_configured() is True
+    # nothing configured
     assert StreamripClient({}).is_configured() is False
+    # partial (token without user_id, password without email) -> not configured
+    assert StreamripClient({"qobuz.auth_token": "tok"}).is_configured() is False
+    assert StreamripClient({"qobuz.password": "p"}).is_configured() is False