caldav 3.x lists niquests as a mandatory dependency and prefers it over
httpx. Passing httpx.BasicAuth via the auth= argument breaks under the
niquests backend with "Unexpected non-callable authentication" — see #731.
Switch CalendarClient.__init__ from auth=Auth|None to keyword-only
password/token, and forward them to AsyncDAVClient as password= plus an
explicit auth_type ("basic" or "bearer"). caldav then builds whichever
auth object its active backend needs (niquests.auth.HTTPBasicAuth or
httpx.BasicAuth), so we stay backend-agnostic.
Threaded raw credentials through NextcloudClient — added keyword-only
password/token to its __init__, and updated from_env, from_token, and
the four call sites that build NextcloudClient (context.py basic-auth
and Login Flow paths, auth/userinfo_routes.py, vector/oauth_sync.py).
Four new unit tests pin the construction wiring so the niquests
regression can't recur silently — basic, bearer, no-creds, and
password-precedence cases.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
