feat: add deployment reload controls

lib/realtime/deployment-refresh.test.ts

@@ -0,0 +1,37 @@
+import { describe, expect, test } from "bun:test";
+import {
+  checkDeploymentVersion,
+  normalizeReloadPrefix,
+  shouldReloadPath,
+} from "@/lib/realtime/deployment-refresh";
+
+describe("deployment refresh policy", () => {
+  test("uses the first version as a baseline and detects later changes", () => {
+    expect(checkDeploymentVersion(null, "build-a")).toEqual({
+      version: "build-a",
+      hasUpdate: false,
+    });
+    expect(checkDeploymentVersion("build-a", "build-a")).toEqual({
+      version: "build-a",
+      hasUpdate: false,
+    });
+    expect(checkDeploymentVersion("build-a", "build-b")).toEqual({
+      version: "build-b",
+      hasUpdate: true,
+    });
+  });
+
+  test("matches global and pathname-prefix reloads", () => {
+    expect(shouldReloadPath(null, "/profile")).toBeTrue();
+    expect(shouldReloadPath("/admin", "/admin/backend")).toBeTrue();
+    expect(shouldReloadPath("/form", "/profile")).toBeFalse();
+  });
+
+  test("normalizes valid prefixes and rejects invalid ones", () => {
+    expect(normalizeReloadPrefix(null)).toBeNull();
+    expect(normalizeReloadPrefix("  /admin  ")).toBe("/admin");
+    expect(() => normalizeReloadPrefix("admin")).toThrow(
+      "Reload path must start with /",
+    );
+  });
+});