fix(contracts): Kind/Policy 单源派生冻结锁；status 整数+域校验；key 放宽注释

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

packages/contracts/test/manifests.test.ts

@@ -57,9 +57,10 @@ describe('RouteManifest 守卫拒绝路径', () => {
     expect(isRouteManifest({ ...validRouteManifest, routes: 'x' })).toBe(false)
   })
 
-  it('routes 元素缺 exact_key 拒绝', () => {
+  it('routes 元素缺 exact_key / 元素为 null 拒绝', () => {
     const { exact_key: _omit, ...route } = validRouteManifest.routes[0]
     expect(isRouteManifest({ ...validRouteManifest, routes: [route] })).toBe(false)
+    expect(isRouteManifest({ ...validRouteManifest, routes: [null] })).toBe(false)
   })
 
   it('status 非数字拒绝（status: "200"）', () => {
@@ -69,6 +70,20 @@ describe('RouteManifest 守卫拒绝路径', () => {
     })).toBe(false)
   })
 
+  it('status 非整数拒绝（200.5）', () => {
+    expect(isRouteManifest({
+      ...validRouteManifest,
+      routes: [{ ...validRouteManifest.routes[0], status: 200.5 }],
+    })).toBe(false)
+  })
+
+  it('status 超域拒绝（999）', () => {
+    expect(isRouteManifest({
+      ...validRouteManifest,
+      routes: [{ ...validRouteManifest.routes[0], status: 999 }],
+    })).toBe(false)
+  })
+
   it('indexable 非布尔拒绝（indexable: 1）', () => {
     expect(isRouteManifest({
       ...validRouteManifest,