fix: correct default alg on keycloak example

Signed-off-by: BoxBoxJason <contact@boxboxjason.dev>

Author: BoxBoxJason

docker-compose.yml

@@ -24,6 +24,7 @@ services:
       - OIDC_DISCOVERY_URL=http://keycloak:8080/realms/excalidash/
       - OIDC_CLIENT_ID=excalidash
       # Local OIDC test secret; align with oidc/keycloak/realm-excalidash.json.
+      - OIDC_ID_TOKEN_SIGNED_RESPONSE_ALG=RS256
       - OIDC_CLIENT_SECRET=excalidash-dev-secret
       - OIDC_REDIRECT_URI=http://localhost:6767/api/auth/oidc/callback
       - OIDC_SCOPES=openid profile email