`vibium bidi-test` fails, WebSocket URL is blank after session creation

[vincebln2]

Description

vibium bidi-test fails at step 3 because the WebSocket URL returned by the WebDriver session is blank. The connection attempt fails with malformed ws or wss URL.

Steps to reproduce:

vibium bidi-test

Expected: all 5 steps pass, including connecting to the BiDi WebSocket

Actual:

[2/5] WebDriver session created with BiDi enabled
      WebSocket URL: 
[3/5] Connecting to BiDi WebSocket...
Error connecting: failed to connect to : malformed ws or wss URL
exit: 1

Environment

vibium v26.5.31 · Chrome for Testing 149.0.7827.115 · macOS 26.5.1

References

#112 (B21)