feat: Token Broker infrastructure (HRT-205)

- PostgreSQL dedie Docker (postgres:16-alpine, port 5434)
- 6 tables: api_tokens, refresh_tokens, token_audit_log, clients, providers, token_usage
- Init SQL + Flask init_db() mis a jour
- Systemd service token-broker (port 8783)
- Deploy script infra/scripts/deploy_token_broker.sh
- Docker compose broker (docker-compose.broker.yml)
- Health check OK: status=ok, database=connected

Co-Authored-By: Paperclip <noreply@paperclip.ing>

services/token-broker/.env.example

@@ -0,0 +1,10 @@
+# Token Broker API — Configuration
+TOKEN_BROKER_PORT=8783
+TOKEN_BROKER_DB_HOST=127.0.0.1
+TOKEN_BROKER_DB_PORT=5434
+TOKEN_BROKER_DB_NAME=token_broker
+TOKEN_BROKER_DB_USER=token_broker
+TOKEN_BROKER_DB_PASSWORD=CHANGE_ME
+TOKEN_BROKER_JWT_SECRET=CHANGE_ME_GENERATE_64_HEX
+TOKEN_BROKER_ACCESS_EXPIRY=900
+TOKEN_BROKER_REFRESH_EXPIRY=2592000