Notification path (bridge.js): entering auth lockout fires ONE desktop
notification per episode (notify-send, critical urgency), only when a session
is detectable (DBUS_SESSION_BUS_ADDRESS or DISPLAY) — headless stays silent.
Message explains the 407 cause and points at 'proxy-bridge reauth'.
Recovery path (proxyctl.js): 'proxy-bridge reauth' prompts masked, verifies the
new password with a SINGLE upstream CONNECT (407 -> NOT stored), stores via
secret-tool on success, then writes a reauth-stamp.json the bridge watches
(1s poll): clears in-memory authState and reloads keyring creds — no restart.
Shared one-shot verifier extracted to verify-creds.js (install.js + proxyctl.js
use the same code; also fixes proxyctl 'setup' shelling to the retired
/opt/setup.js — 'reauth' is its replacement for the password-expiry flow).
Tests: +3 bridge (notify once-per-episode incl. remediation hint; headless
silent; stamp clears lockout without restart) +2 proxyctl (verified stored +
stamped; rejected never stored/stamped). Suite: 28/28.
