Immich has full native OIDC support (its own docs list Authelia as a
supported provider), but needed more than the single-redirect-URI
model _authelia_add_oidc_client() previously supported: it requires
three redirect_uris at once (web login, account-linking page, and the
mobile app's app.immich:///oauth-callback custom-scheme redirect).
Generalized redirect-URI handling from a scalar REDIRECT_PATH to two
arrays (domain-relative REDIRECT_PATHS, plus already-complete
EXTRA_REDIRECT_URIS for non-domain-based ones like the mobile scheme)
and build the YAML redirect_uris list from however many are present.
ActualBudget/Vaultwarden/Other still resolve to a single-entry array,
so their generated config is unchanged. Verified the multi-entry YAML
generation against a python yaml parser before wiring it in, and the
case-statement/array logic in isolation against the real file's code.