Add environment configuration and documentation for various services

- Created .env.example files for Kafka, Kibana, KodBox, Kong, Langfuse, Logstash, n8n, Nginx, OceanBase, OpenCoze, RocketMQ, TiDB, and TiKV.
- Added README.md and README.zh.md files for OceanBase, RocketMQ, TiDB, and TiKV, detailing usage, configuration, and access instructions.
- Implemented docker-compose.yaml files for OceanBase, RocketMQ, TiDB, and TiKV, defining service configurations, health checks, and resource limits.
- Included broker.conf for RocketMQ to specify broker settings.
- Established a consistent timezone (UTC) across all services.
- Provided optional port overrides in .env.example files for flexibility in deployment.

src/n8n/.env.example

@@ -0,0 +1,38 @@
+# n8n version
+N8N_VERSION=1.114.0
+
+# Timezone
+TZ=UTC
+GENERIC_TIMEZONE=UTC
+
+# Port
+N8N_PORT=5678
+
+# Basic auth
+N8N_BASIC_AUTH_ACTIVE=true
+N8N_BASIC_AUTH_USER=
+N8N_BASIC_AUTH_PASSWORD=
+
+# Host configuration
+N8N_HOST=0.0.0.0
+N8N_PROTOCOL=http
+WEBHOOK_URL=http://localhost:5678/
+
+# Database configuration (SQLite by default, PostgreSQL optional)
+DB_TYPE=sqlite
+DB_POSTGRESDB_DATABASE=n8n
+DB_POSTGRESDB_HOST=n8n-db
+DB_POSTGRESDB_PORT=5432
+DB_POSTGRESDB_USER=n8n
+DB_POSTGRESDB_PASSWORD=
+
+# Execution mode
+EXECUTIONS_MODE=regular
+
+# Encryption key (generate with: openssl rand -base64 32)
+N8N_ENCRYPTION_KEY=
+
+# PostgreSQL configuration (if using PostgreSQL)
+POSTGRES_USER=n8n
+POSTGRES_PASSWORD=n8n
+POSTGRES_DB=n8n