feat: 初始化ERP平台底座项目结构

- 添加基础crate结构(erp-core, erp-common)
- 实现核心模块trait和事件总线
- 配置Docker开发环境(PostgreSQL+Redis)
- 添加Tauri桌面端基础框架
- 设置CI/CD工作流
- 编写项目协作规范文档(CLAUDE.md)

crates/erp-server/src/db.rs

@@ -0,0 +1,16 @@
+use sea_orm::{ConnectOptions, Database, DatabaseConnection};
+use std::time::Duration;
+
+use crate::config::DatabaseConfig;
+
+pub async fn connect(config: &DatabaseConfig) -> anyhow::Result<DatabaseConnection> {
+    let mut opt = ConnectOptions::new(&config.url);
+    opt.max_connections(config.max_connections)
+        .min_connections(config.min_connections)
+        .connect_timeout(Duration::from_secs(10))
+        .idle_timeout(Duration::from_secs(600));
+
+    let db = Database::connect(opt).await?;
+    tracing::info!("Database connected successfully");
+    Ok(db)
+}