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-core/src/module.rs

@@ -0,0 +1,76 @@
+use axum::Router;
+use uuid::Uuid;
+
+use crate::error::AppResult;
+use crate::events::EventBus;
+
+/// 模块注册接口
+/// 所有业务模块（Auth, Workflow, Message, Config, 行业模块）都实现此 trait
+pub trait ErpModule: Send + Sync {
+    /// 模块名称（唯一标识）
+    fn name(&self) -> &str;
+
+    /// 模块版本
+    fn version(&self) -> &str {
+        env!("CARGO_PKG_VERSION")
+    }
+
+    /// 依赖的其他模块名称
+    fn dependencies(&self) -> Vec<&str> {
+        vec![]
+    }
+
+    /// 注册 Axum 路由
+    fn register_routes(&self, router: Router) -> Router;
+
+    /// 注册事件处理器
+    fn register_event_handlers(&self, _bus: &EventBus) {}
+
+    /// 租户创建时的初始化钩子
+    fn on_tenant_created(
+        &self,
+        _tenant_id: Uuid,
+    ) -> impl std::future::Future<Output = AppResult<()>> + Send {
+        async { Ok(()) }
+    }
+
+    /// 租户删除时的清理钩子
+    fn on_tenant_deleted(
+        &self,
+        _tenant_id: Uuid,
+    ) -> impl std::future::Future<Output = AppResult<()>> + Send {
+        async { Ok(()) }
+    }
+}
+
+/// 模块注册器
+pub struct ModuleRegistry {
+    modules: Vec<Box<dyn ErpModule>>,
+}
+
+impl ModuleRegistry {
+    pub fn new() -> Self {
+        Self { modules: vec![] }
+    }
+
+    pub fn register(&mut self, module: Box<dyn ErpModule>) {
+        tracing::info!(module = module.name(), version = module.version(), "Module registered");
+        self.modules.push(module);
+    }
+
+    pub fn build_router(&self, base: Router) -> Router {
+        self.modules
+            .iter()
+            .fold(base, |router, m| m.register_routes(router))
+    }
+
+    pub fn register_handlers(&self, bus: &EventBus) {
+        for module in &self.modules {
+            module.register_event_handlers(bus);
+        }
+    }
+
+    pub fn modules(&self) -> &[Box<dyn ErpModule>] {
+        &self.modules
+    }
+}