feat(migration): V6 系统设置/二次分配/审批表与角色参数种子

- 新增 system_settings（公司信息单行）/ business_secondary_allocations（二次
  分配明细，比例不强制合计满额，分摊计算待澄清另批）/ approval_orders+
  approval_steps（三级审批状态机，开关关闭自动通过留痕）
- roles 种子新增营销后勤/财务/领导三职能角色；内置保护改 BUILTIN_ROLE_CODES
  白名单（roles 表无 is_builtin 列，不加列）
- PARAM_REGISTRY 首例 BOOL：两个审批开关（16→18 项，种子双写）
- 双轨同步：V6 导出 SQL + init-dev.sql（表/索引/种子/版本号 79bcc5aa98d4）
- 测试同步：EXPECTED_TABLES 四新表、角色种子断言 5 角色、目录断言 18 项
  八分组、BOOL 校验边界；迁移 downgrade 修 1553（只保留 drop_table）并补
  行级种子反向清理

Co-Authored-By: Claude Code <noreply@anthropic.com>

backend/tests/unit/test_param_registry.py

@@ -18,7 +18,7 @@ from app.services.param_registry import (
     validate_and_normalize,
 )
 
-# 与 db/migration/V3 迁移种子保持一致的 16 项编码
+# 与 db/migration 迁移种子保持一致的 18 项编码（V3 十六项 + V6 审批开关两项）
 EXPECTED_CODES = {
     "salesperson.rate.start",
     "salesperson.rate.slope",
@@ -36,14 +36,16 @@ EXPECTED_CODES = {
     "salary.basic.mode",
     "probation.annual.threshold",
     "probation.salary.basic",
+    "approval.secondary_allocation.enabled",
+    "approval.monthly_settlement.enabled",
 }
 
 
 class TestRegistry:
     """注册表元数据完整性（与迁移种子同源）。"""
 
-    def test_注册表共16项(self) -> None:
-        assert len(PARAM_REGISTRY) == 16
+    def test_注册表共18项(self) -> None:
+        assert len(PARAM_REGISTRY) == 18
 
     def test_编码集合与迁移种子一致(self) -> None:
         assert set(PARAM_REGISTRY) == EXPECTED_CODES
@@ -61,10 +63,27 @@ class TestRegistry:
                 continue
             if spec.value_type in {"DECIMAL", "INT"}:
                 parse_fraction(spec.default_value)  # 不可解析会抛 BadRequestError
+            elif spec.value_type == "BOOL":
+                assert spec.default_value in {"0", "1"}, f"{spec.code} 默认值非 0/1"
             elif spec.value_type == "ENUM":
                 assert spec.options, f"{spec.code} 为 ENUM 但无选项"
                 assert spec.default_value in spec.options
 
+    def test_BOOL开关_仅接受0与1(self) -> None:
+        """V6 首例 BOOL 注册的两个审批开关：合法值与非法值边界。"""
+        for code in (
+            "approval.secondary_allocation.enabled",
+            "approval.monthly_settlement.enabled",
+        ):
+            spec = PARAM_REGISTRY[code]
+            assert spec.value_type == "BOOL"
+            assert validate_and_normalize(spec, "0") == "0"
+            assert validate_and_normalize(spec, "1") == "1"
+            with pytest.raises(BadRequestError):
+                validate_and_normalize(spec, "true")
+            with pytest.raises(BadRequestError):
+                validate_and_normalize(spec, "2")
+
     def test_取值域上下限可解析(self) -> None:
         for spec in PARAM_REGISTRY.values():
             if spec.value_min is not None: