Portal sign-in with the Ecare office login

Ecare staff sign in with their office username and password, checked by
the Ecare sign-in service from the backend (AUTH_TOKEN_API_URL); a good
Ecare login still needs a Portal User. Service down = "try again
shortly", never a wrong password. /api/auth/login, me, logout; sign-in
tries limited per address. Users page: Ecare office login or Portal
password per user. Context.md: 27/10 runs, the login retry bug.
71 test files, 1239 tests.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/ecw_bot/settings.py

@@ -694,6 +694,10 @@ RESULTS_DB_CONN = _env(
 # only on the Windows PC.
 PORTAL_URLS = _env("PORTAL_URLS")
 PORTAL_SERVER = _env_bool("PORTAL_SERVER", False)
+# The Ecare office sign-in service (2026-10-27), e.g.
+# https://auth-wfm.ecareindia.com/api/login/token. Empty: Portal passwords
+# only.
+AUTH_TOKEN_API_URL = _env("AUTH_TOKEN_API_URL")
 
 # eCW builds the file server-side over a wide date range, so this is generous.
 DOWNLOAD_TIMEOUT = _env_int("DOWNLOAD_TIMEOUT_MS", 300_000)   # 5 min