test: E2E auth fixture 修复 + Workflow 集成测试

- E2E: 用 addInitScript 替代 goto+evaluate 注入 localStorage，
  解决 Zustand store 初始化时序问题 (10/10 通过)
- E2E: 修复 Modal 按钮选择器 (OK/Cancel 替代中文)
- E2E: Playwright 配置对齐端口 5174
- 集成测试: 新增 workflow_tests 模块 (4 个测试)

crates/erp-server/Cargo.toml

@@ -37,4 +37,5 @@ testcontainers = "0.23"
 testcontainers-modules = { version = "0.11", features = ["postgres"] }
 erp-auth = { workspace = true }
 erp-plugin = { workspace = true }
+erp-workflow = { workspace = true }
 erp-core = { workspace = true }