Gitea 1.25.5 and earlier do not send PKCE code_challenge_method
on OIDC sources, so enforcing PKCE in Keycloak causes:
Missing parameter: code_challenge_method
at the /auth endpoint. Drop the pkce.code.challenge.method
attribute from the ecosplay_code client block in the realm
import JSON, and add a set_client_pkce helper to sync.sh that
clears the attribute on existing installs. All other clients
(ecosplay_web, eticket) keep S256.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>