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

The Authentik SSO button returned "Server Error" (500) because the grafana
provider authorization_flow was NULL 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); read claims from the id_token
(USE_ID_TOKEN=true) and drop ?api=1 from the API URL (Grafana v13 turns it into
a /emails 404); pin email/sub/preferred_username attribute paths; allow
first-login provisioning 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; the grafana-email-scope mapping that returned
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

@@ -47,9 +47,23 @@ 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/
-# ?api=1 = introspection-style userinfo: returns custom claims (groups) too.
-Environment=GF_AUTH_GENERIC_OAUTH_API_URL=https://auth.franksdank.cloud/application/o/userinfo/?api=1
-Environment=GF_AUTH_GENERIC_OAUTH_ALLOW_SIGN_UP=false
+# 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
+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.
+# Quoted: quadlet word-splits Environment=, so an unquoted spaced list
+# truncates SCOPES to its first token.
+Environment="GF_AUTH_GENERIC_OAUTH_SCOPES=openid email profile"
+Environment=GF_AUTH_GENERIC_OAUTH_EMAIL_ATTRIBUTE_PATH=email
+Environment=GF_AUTH_GENERIC_OAUTH_LOGIN_ATTRIBUTE_PATH=sub
+Environment=GF_AUTH_GENERIC_OAUTH_NAME_ATTRIBUTE_PATH=preferred_username
+# First SSO login auto-provisions the user. Safe: unauthenticated traffic never
+# reaches this callback — the Anubis -> Authentik guard fronts every request.
+Environment=GF_AUTH_GENERIC_OAUTH_ALLOW_SIGN_UP=true
 Environment=GF_AUTH_GENERIC_OAUTH_AUTO_UPSERT=true
 Environment=GF_AUTH_GENERIC_OAUTH_ALLOW_ASSIGN_ORG=true
 Environment=GF_AUTH_GENERIC_OAUTH_ORG_ID=1