fix: scope Node version constraint to ai-isolate-node (Node >= 22 for isolated-vm)

The previous "Node 24+" claim was overreaching:

- Only `@tanstack/ai-isolate-node` (via `isolated-vm`) has a Node version
  floor. Everything else in the workspace runs fine on older Node.
- `isolated-vm`'s actual `engines.node` is `>=22.0.0` (see
  https://github.com/laverdet/isolated-vm/blob/main/package.json), not 24.

Changes:
- Root package.json: drop the `node: ">=24"` entry from engines (keep the
  pnpm constraint). No global Node floor for development.
- packages/typescript/ai-isolate-node/package.json: bump `engines.node`
  from `>=18` to `>=22` to match upstream.
- packages/typescript/ai-isolate-node/README.md: same — say `>=22`, and
  add the `--no-node-snapshot` flag note for Node 20+ runtime usage.

Author: AlemTuzlak

package.json

@@ -8,7 +8,6 @@
   "packageManager": "pnpm@11.1.1",
   "type": "module",
   "engines": {
-    "node": ">=24",
     "pnpm": ">=11.0.0"
   },
   "scripts": {

packages/typescript/ai-isolate-node/README.md

@@ -4,8 +4,9 @@ Node.js V8 isolate driver for TanStack AI Code Mode. Uses [`isolated-vm`](https:
 
 ## Requirements
 
-- Node.js >= 18
+- Node.js >= 22 (matches [`isolated-vm`'s engine constraint](https://github.com/laverdet/isolated-vm/blob/main/package.json))
 - Native compilation toolchain (the `isolated-vm` package compiles a native addon)
+- On Node.js 20.x and later, pass `--no-node-snapshot` when running `node`
 
 ## Installation
 

packages/typescript/ai-isolate-node/package.json

@@ -20,7 +20,7 @@
   },
   "sideEffects": false,
   "engines": {
-    "node": ">=18"
+    "node": ">=22"
   },
   "files": [
     "dist",