i open and start a long-term project to implement a database for gaining a deep understanding of modern database architecture and implementation

this project is an extend project of [go-redis-fallback](https://github.com/pardnchiu/go-redis-fallback), to use same cache skill to build a tcp connection database with aof logging and mongodb-like query features

with projects web-monitor, cim-prototype, rss-reader, im skilled in cmd parse and set action, so the next step is to build my own database for sharing

i already completed these features

Complete Database System Architecture - TCP Server: Implements a TCP server listening on `127.0.0.1:7989` - CLI Client: Supports `cli` interaction and command execution mode (`-c` parameter) - Multi-Database Support: Allows switching and isolated storage for up to 16 databases (0-15)

Basic KV Operation System - Core Operations: Fully implements `GET`, `SET`, `DEL`, `EXISTS`, `TYPE` - Pattern Matching: `KEYS` command supports wildcard search with `*` and `?` - TTL Management: Fully implements `TTL`, `EXPIRE`, `PERSIST`, with automatic expiration cleanup - Type System: Automatically detects types like `string`, `int`, `object`, `array`

Dual Storage System - AOF Persistence: Logs commands and supports automatic recovery on startup - File Caching: MD5 hash-based three-level directory structure (data/0/ab/cd/ef/hash.json) - JSON Format: Includes `created_at`, `updated_at`, `expire_at`