Two fixes surfaced while testing Login Flow v2 provisioning behind a split
internal/external host (Docker: server↔Nextcloud over http://app, browser
over http://localhost:8080):
1. login_url pointed at the internal host. Nextcloud builds the login URL
from the request host, so the browser-facing URL came back as
http://app/login/v2/flow/... — unreachable from the user's browser. The
poll endpoint was already rewritten to the internal host (correct, the
server polls it); now LoginFlowV2Client also rewrites the login_url origin
to settings.nextcloud_public_issuer_url when set (passed at all 5
construction sites). When unset, behaviour is unchanged.
2. The app-password format guard rejected raw session tokens. core/
getapppassword returns a long alphanumeric token, not the dashed 25-char
Security-settings format, so the dashed-only regex 400'd the one-click
opt-in handoff. Relax APP_PASSWORD_PATTERN to `^[a-zA-Z0-9-]{20,256}$`;
the authoritative validation is still the BasicAuth check against Nextcloud.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>