fix: require Node.js v22.18.0+ for functions SDK (#672)

This change adds an "engines" field to the package.json files of the
`@gram-ai/functions` requiring Node.js version 22.18.0 or higher. This
ensures that we are in a runtime that supports import assertions and
native support for running TypeScript files without experimental flags.

Author: disintegrator

.changeset/lemon-dragons-find.md

@@ -0,0 +1,8 @@
+---
+"@gram-ai/functions": patch
+---
+
+Added an "engines" field to the package.json files of the `@gram-ai/functions`
+requiring Node.js version 22.18.0 or higher. This ensures that we are in a
+runtime that supports import assertions and native support for running
+TypeScript files without experimental flags.

ts-framework/functions/package.json

@@ -8,6 +8,9 @@
   "keywords": [],
   "license": "MIT",
   "homepage": "https://github.com/speakeasy-api/gram",
+  "engines": {
+    "node": ">=22.18.0"
+  },
   "repository": {
     "type": "git",
     "url": "https://github.com/speakeasy-api/gram.git",