Quick Connect (the DEFAULT add-connection mode) has no username field, so every
auth-build site (username && password ? {..} : undefined) produced undefined auth
whenever a password was set but username empty -> NO Authorization header -> 401
against a password-protected server. This is the common setup
(OPENCODE_SERVER_PASSWORD=... opencode serve) and a top install->churn cause:
user sets a password, can't connect, gives up.
Fix: extract buildAuth() to a pure, testable module; when a password is present but
username is empty, default username to 'opencode' (the server's own default,
OPENCODE_SERVER_USERNAME ?? 'opencode'). Advanced mode's explicit username is
preserved. Replaced all 6 inline ternaries in connections.ts.
+3 regression tests (68 total pass), typecheck clean. Found while setting up an
on-device emulator test of the connect flow.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
