docs: reconstruct READMEs

clickhouse/README.md

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+# ClickHouse
+
+High-performance columnar OLAP database for analytics and data warehousing:
+
+- Columnar storage for fast analytical queries
+- Real-time data ingestion and processing
+- Horizontal scaling for large datasets
+- SQL interface with advanced analytics functions
+- Integration with External Secrets for secure credential management
+- Support for various data formats (CSV, JSON, Parquet, etc.)
+
+## Installation
+
+```bash
+just clickhouse::install
+```
+
+## Access
+
+Access ClickHouse at `https://clickhouse.yourdomain.com` using the admin credentials stored in Vault.
+
+## CH-UI Web Interface
+
+An optional web-based query interface for ClickHouse is available:
+
+```bash
+just ch-ui::install
+```