feat(FN-2540): extract shared route context and integrated router registrar

- Refactor dashboard routing to use a shared route context scaffold for provider-safe registration
- Add register-integrated-routers helper and wire routes.ts to compose integrated routers cleanly
- Update route documentation and route types to reflect the new context/registrar structure
- Stabilize quick-entry clear assertion and add routing tests covering integrated router registration behavior

packages/dashboard/app/components/__tests__/ListView.test.tsx

@@ -1574,9 +1574,8 @@ describe("ListView Quick Entry", () => {
 
     await waitFor(() => {
       expect(mockOnQuickCreate).toHaveBeenCalled();
+      expect(input.value).toBe("");
     });
-
-    expect(input.value).toBe("");
   });
 
   it("shows error toast when onQuickCreate fails and keeps input content", async () => {