Fix: Add explicit OIDC redirect URI for Keycloak auth

Added force-redirect-https-scheme and explicit redirect-uri to fix
'Paramètre invalide : redirect_uri' error in Keycloak authentication.

Changes:
- quarkus.oidc.authentication.force-redirect-https-scheme=true
- quarkus.oidc.authentication.redirect-uri=https://unionflow.lions.dev/auth/callback

This ensures Quarkus OIDC uses the correct absolute URL for redirect
instead of constructing it from request headers (which may be incorrect
behind nginx ingress).

src/main/resources/application-prod.properties

@@ -69,6 +69,8 @@ quarkus.oidc.client-id=unionflow-client
 quarkus.oidc.credentials.secret=${KEYCLOAK_CLIENT_SECRET}
 quarkus.oidc.application-type=web-app
 quarkus.oidc.authentication.redirect-path=/auth/callback
+quarkus.oidc.authentication.force-redirect-https-scheme=true
+quarkus.oidc.authentication.redirect-uri=https://unionflow.lions.dev/auth/callback
 quarkus.oidc.authentication.restore-path-after-redirect=true
 quarkus.oidc.authentication.scopes=openid,profile,email,roles
 quarkus.oidc.token.issuer=https://security.lions.dev/realms/unionflow