feat: initialize Nuanji (Warm Notes) project

- Base platform from base.git (ERP base: auth, core, config, message, workflow, plugin)
- Created erp-diary module skeleton (lib.rs, dto.rs, error.rs, event.rs, state.rs)
- Integrated erp-diary into workspace and erp-server
- Added DiaryModule registration in main.rs
- Added DiaryState FromRef in state.rs
- Diary routes mounted (empty routes, ready for implementation)
- Product design spec v1.2 preserved in docs/
- Implementation plan preserved in plans/

Cargo check: OK
Cargo test: OK (78+ base tests passing)

crates/erp-server/tests/integration/test_db.rs

@@ -0,0 +1,114 @@
+use sea_orm::{ConnectionTrait, Database, DatabaseBackend, Statement};
+use std::sync::Arc;
+
+use erp_server_migration::MigratorTrait;
+
+/// 全局信号量：限制同时创建数据库的测试数量，避免 PostgreSQL 连接耗尽
+static DB_SEMAPHORE: std::sync::OnceLock<Arc<tokio::sync::Semaphore>> = std::sync::OnceLock::new();
+
+fn db_semaphore() -> &'static Arc<tokio::sync::Semaphore> {
+    DB_SEMAPHORE.get_or_init(|| Arc::new(tokio::sync::Semaphore::new(4)))
+}
+
+/// 测试数据库 — 使用本地 PostgreSQL 创建隔离测试库
+///
+/// 连接本地 PostgreSQL（wiki/infrastructure.md 配置），为每个测试创建独立的测试数据库。
+/// 不依赖 Docker/Testcontainers，与开发环境一致。
+pub struct TestDb {
+    db: Option<sea_orm::DatabaseConnection>,
+    db_name: String,
+    _permit: Option<tokio::sync::OwnedSemaphorePermit>,
+}
+
+impl TestDb {
+    pub async fn new() -> Self {
+        let permit = db_semaphore()
+            .clone()
+            .acquire_owned()
+            .await
+            .expect("信号量获取失败");
+
+        let db_name = format!("erp_test_{}", uuid::Uuid::now_v7().simple());
+
+        let admin_url = std::env::var("TEST_DB_URL")
+            .unwrap_or_else(|_| "postgres://postgres:123123@localhost:5432/postgres".to_string());
+
+        let admin_db = Database::connect(&admin_url)
+            .await
+            .expect("连接本地 PostgreSQL 失败，请确认服务正在运行");
+
+        admin_db
+            .execute(Statement::from_string(
+                DatabaseBackend::Postgres,
+                format!("CREATE DATABASE \"{}\"", db_name),
+            ))
+            .await
+            .expect("创建测试数据库失败");
+
+        drop(admin_db);
+
+        // 从 admin_url 推导测试库 URL（替换路径部分）
+        let test_url = if let Some(pos) = admin_url.rfind('/') {
+            format!("{}/{}", &admin_url[..pos], db_name)
+        } else {
+            format!("postgres://postgres:123123@localhost:5432/{}", db_name)
+        };
+        let db = Database::connect(&test_url)
+            .await
+            .expect("连接测试数据库失败");
+
+        // 运行所有迁移
+        erp_server_migration::Migrator::up(&db, None)
+            .await
+            .expect("执行数据库迁移失败");
+
+        Self {
+            db: Some(db),
+            db_name,
+            _permit: Some(permit),
+        }
+    }
+
+    /// 获取数据库连接引用
+    pub fn db(&self) -> &sea_orm::DatabaseConnection {
+        self.db.as_ref().expect("数据库连接已被释放")
+    }
+}
+
+impl Drop for TestDb {
+    fn drop(&mut self) {
+        let db_name = self.db_name.clone();
+        self.db.take();
+
+        // 尝试在独立线程中清理，避免在 tokio runtime 内创建新 runtime
+        let _ = std::thread::spawn(move || {
+            let rt = tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build();
+            if let Ok(rt) = rt {
+                rt.block_on(async {
+                    let admin_url = std::env::var("TEST_DB_URL")
+                        .unwrap_or_else(|_| "postgres://postgres:123123@localhost:5432/postgres".to_string());
+                    if let Ok(admin_db) = Database::connect(&admin_url).await {
+                        let disconnect_sql = format!(
+                            "SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname = '{}'",
+                            db_name
+                        );
+                        admin_db
+                            .execute(Statement::from_string(DatabaseBackend::Postgres, disconnect_sql))
+                            .await
+                            .ok();
+
+                        admin_db
+                            .execute(Statement::from_string(
+                                DatabaseBackend::Postgres,
+                                format!("DROP DATABASE IF EXISTS \"{}\"", db_name),
+                            ))
+                            .await
+                            .ok();
+                    }
+                });
+            }
+        });
+    }
+}