fix(observability): repair Grafana Authentik OAuth2 relying-party login

The Authentik SSO button returned "Server Error" (500): the grafana provider had
a NULL authorization_flow and the authorize view crashed building a None flow
planner. After that, the login failed with "InternalError" — no email claim
reached Grafana, so it fell back to GET <api_url>/emails, which authentik 404s.

Unit env: request authentik real scopes (openid email profile, not the GitLab
user:email that crashes the authorize view); standard userinfo API_URL with no
?api=1 (Grafana v13 turns ?api=1 into a /emails 403); email/sub/preferred_username
attribute paths; ALLOW_SIGN_UP=true since the Anubis->Authentik guard fronts the
callback. scripts/authentik-grafana-sso-fix.sh idempotently re-applies the two
IdP-side causes (NULL authorization_flow; grafana-email-scope returning a bare
string instead of {"email":..}). Verified end to end: RP login lands on / and
/api/user answers 200 with the real email, user provisioned as Viewer.

dankclaw/observability/quadlet/grafana.container

@@ -47,11 +47,12 @@ Environment=GF_AUTH_GENERIC_OAUTH_CLIENT_SECRET=${GRAFANA_OAUTH_CLIENT_SECRET}
 # client_id query parameter — /application/o/<slug>/authorize/ does not exist.
 Environment=GF_AUTH_GENERIC_OAUTH_AUTH_URL=https://auth.franksdank.cloud/application/o/authorize/
 Environment=GF_AUTH_GENERIC_OAUTH_TOKEN_URL=https://auth.franksdank.cloud/application/o/token/
-# Read claims from the signed ID token. Grafana v13 always appends /emails to
-# API_URL and GETs it as a userinfo endpoint (authentik has no such path and
-# 404s it, failing the login). USE_ID_TOKEN makes Grafana take sub/email/name
-# from the id_token, which authentik fills from the openid/email/profile scopes.
-Environment=GF_AUTH_GENERIC_OAUTH_USE_ID_TOKEN=true
+# Standard OIDC userinfo. Grafana v13 fetches <api_url>/emails for the address
+# ONLY when the token carries no `email` claim (authentik has no /emails path and
+# 404s it, failing the login) — so the claim must actually be there: the fix is
+# the grafana-email-scope mapping (see scripts/authentik-grafana-sso-fix.sh),
+# not a Grafana flag. Do NOT append ?api=1 to this URL: Grafana then GETs
+# <...>/userinfo/?api=1/emails, a 403.
 Environment=GF_AUTH_GENERIC_OAUTH_API_URL=https://auth.franksdank.cloud/application/o/userinfo/
 # authentik's scopes are openid/email/profile. `user:email` (a GitLab-ism) is
 # not a known scope here; requesting it makes the authorize view crash.