perf: skip cache-busting for bundled hooks, use mtime for workspace hooks (openclaw#16960) thanks @mudrii

Verified:
- pnpm build
- pnpm check
- pnpm test:macmini

Co-authored-by: mudrii <220262+mudrii@users.noreply.github.com>
Co-authored-by: Tak Hoffman <781889+Takhoffman@users.noreply.github.com>

src/hooks/import-url.test.ts

@@ -0,0 +1,62 @@
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { describe, it, expect, beforeEach, afterEach } from "vitest";
+import { buildImportUrl } from "./import-url.js";
+
+describe("buildImportUrl", () => {
+  let tmpDir: string;
+  let tmpFile: string;
+
+  beforeEach(() => {
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), "import-url-test-"));
+    tmpFile = path.join(tmpDir, "handler.js");
+    fs.writeFileSync(tmpFile, "export default () => {};");
+  });
+
+  afterEach(() => {
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+  });
+
+  it("returns bare URL for bundled hooks (no query string)", () => {
+    const url = buildImportUrl(tmpFile, "openclaw-bundled");
+    expect(url).not.toContain("?t=");
+    expect(url).toMatch(/^file:\/\//);
+  });
+
+  it("appends mtime-based cache buster for workspace hooks", () => {
+    const url = buildImportUrl(tmpFile, "openclaw-workspace");
+    expect(url).toMatch(/\?t=[\d.]+&s=\d+/);
+
+    const { mtimeMs, size } = fs.statSync(tmpFile);
+    expect(url).toContain(`?t=${mtimeMs}`);
+    expect(url).toContain(`&s=${size}`);
+  });
+
+  it("appends mtime-based cache buster for managed hooks", () => {
+    const url = buildImportUrl(tmpFile, "openclaw-managed");
+    expect(url).toMatch(/\?t=[\d.]+&s=\d+/);
+  });
+
+  it("appends mtime-based cache buster for plugin hooks", () => {
+    const url = buildImportUrl(tmpFile, "openclaw-plugin");
+    expect(url).toMatch(/\?t=[\d.]+&s=\d+/);
+  });
+
+  it("returns same URL for bundled hooks across calls (cacheable)", () => {
+    const url1 = buildImportUrl(tmpFile, "openclaw-bundled");
+    const url2 = buildImportUrl(tmpFile, "openclaw-bundled");
+    expect(url1).toBe(url2);
+  });
+
+  it("returns same URL for workspace hooks when file is unchanged", () => {
+    const url1 = buildImportUrl(tmpFile, "openclaw-workspace");
+    const url2 = buildImportUrl(tmpFile, "openclaw-workspace");
+    expect(url1).toBe(url2);
+  });
+
+  it("falls back to Date.now() when file does not exist", () => {
+    const url = buildImportUrl("/nonexistent/handler.js", "openclaw-workspace");
+    expect(url).toMatch(/\?t=\d+/);
+  });
+});