✨ Add howto function and update metadata for new script file

This change introduces a new asynchronous `howto` function in `deno-ai-mod.ts` that fetches command-line how-to summaries, modifies existing functions to use a new `getBearerToken` utility, and adds metadata for the new `howto.ts` script in `script-meta-v2.json`.

single-scripts/howto.ts

@@ -0,0 +1,25 @@
+#!/usr/bin/env runts -- --allow-all
+
+import {log, ProcessBar,} from "https://script.hatter.ink/@67/deno-commons-mod.ts";
+import {howto} from "https://script.hatter.ink/@1/deno-ai-mod.ts";
+
+async function main() {
+    const message = prompt("Input your message: ");
+    if (!message) {
+        throw new Error("Message is required");
+    }
+    const summary = await new ProcessBar("AI howto").call(
+        async (): Promise<string> => {
+            return await howto(message);
+        },
+    );
+    log.success(`AI howto command line message: \n${summary}`);
+}
+
+main().catch((err) => {
+    log.error(err);
+    process.exit(0);
+}).then(() => process.exit(0));
+
+// @SCRIPT-SIGNATURE-V1: yk-r1.ES256.20260412T135106+08:00.MEQCICWC9h53VEbG8dkDhZRg
+// LBcxOktVwEDhnmlQU0MDXiCEAiAB3frJ/GSnacJJ6FXmljy8NmL9kFbqg6hBJUn49QOOYA==