Discord-reported: clicking the Tidal "Authenticate" button on a
Docker setup landed users on a remote-access instructions page that
told them their callback URL would look like
http://127.0.0.1:8888/tidal/callback?code=... — Spotify's port,
hardcoded into the Tidal instructions. Users who followed those
instructions literally saved 8888 into their tidal.redirect_uri
setting; that mismatched their Tidal Developer App's registered
:8889 redirect URI and Tidal returned error 1002 (invalid redirect
URI) on every auth attempt.
Pull the port from the actual TidalClient.redirect_uri the OAuth
URL was just built with (urlparse), with the SOULSYNC_TIDAL_CALLBACK_PORT
env var as fallback when the URI can't be parsed. Both the Step 2
example and the Step 3 highlighted URL now reflect whatever Tidal
port the user is actually configured to use.
Adds 3 regression tests covering the reported scenario, custom
callback ports via SOULSYNC_TIDAL_CALLBACK_PORT, and a defensive
fallback when redirect_uri is unparseable. Tests hit the real
/auth/tidal route through Flask's test client and assert the
rendered HTML, so future hardcoded ports get caught immediately.
