[Config] Split Keycloak config by local/dev/prod profiles

[egorkuzn]

Why\nSingle application.yaml is not enough for stable local and deployment flows. We need profile-specific config for Keycloak issuer/client/audience.\n\n## Scope\n- Keep minimal base application.yaml.\n- Add application-local.yaml, application-dev.yaml, application-prod.yaml.\n- Move issuer/client/audience to env-driven profile configs.\n\n## DoD\n- Local profile works with sensible defaults.\n- Dev/prod profiles rely on explicit env vars.