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.ts

@@ -0,0 +1,38 @@
+/**
+ * Build an import URL for a hook handler module.
+ *
+ * Bundled hooks (shipped in dist/) are immutable between installs, so they
+ * can be imported without a cache-busting suffix — letting V8 reuse its
+ * module cache across gateway restarts.
+ *
+ * Workspace, managed, and plugin hooks may be edited by the user between
+ * restarts. For those we append `?t=<mtime>&s=<size>` so the module key
+ * reflects on-disk changes while staying stable for unchanged files.
+ */
+
+import fs from "node:fs";
+import { pathToFileURL } from "node:url";
+import type { HookSource } from "./types.js";
+
+/**
+ * Sources whose handler files never change between `npm install` runs.
+ * Imports from these sources skip cache busting entirely.
+ */
+const IMMUTABLE_SOURCES: ReadonlySet<HookSource> = new Set(["openclaw-bundled"]);
+
+export function buildImportUrl(handlerPath: string, source: HookSource): string {
+  const base = pathToFileURL(handlerPath).href;
+
+  if (IMMUTABLE_SOURCES.has(source)) {
+    return base;
+  }
+
+  // Use file metadata so the cache key only changes when the file changes
+  try {
+    const { mtimeMs, size } = fs.statSync(handlerPath);
+    return `${base}?t=${mtimeMs}&s=${size}`;
+  } catch {
+    // If stat fails (unlikely), fall back to Date.now() to guarantee freshness
+    return `${base}?t=${Date.now()}`;
+  }
+}