fix(#410): pass OIDC_ENABLED to API container in docker-compose

The genericOAuth plugin is conditionally loaded based on OIDC_ENABLED
env var. Without it, BetterAuth has no /sign-in/oauth2 route, causing
404 when the login button is clicked.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -364,6 +364,7 @@ services:
       # Cache
       VALKEY_URL: redis://valkey:6379
       # Authentication
+      OIDC_ENABLED: ${OIDC_ENABLED:-false}
       OIDC_ISSUER: ${OIDC_ISSUER}
       OIDC_CLIENT_ID: ${OIDC_CLIENT_ID}
       OIDC_CLIENT_SECRET: ${OIDC_CLIENT_SECRET}

docker/docker-compose.build.yml

@@ -374,6 +374,7 @@ services:
       # Cache
       VALKEY_URL: redis://valkey:6379
       # Authentication
+      OIDC_ENABLED: ${OIDC_ENABLED:-false}
       OIDC_ISSUER: ${OIDC_ISSUER}
       OIDC_CLIENT_ID: ${OIDC_CLIENT_ID}
       OIDC_CLIENT_SECRET: ${OIDC_CLIENT_SECRET}