fix(dev-server-legacy): add --experimental-strip-types to test script

CI sets NODE_OPTIONS='--no-experimental-strip-types' to support
un-migrated mocha+ts-node packages. The CLI flag overrides NODE_OPTIONS,
letting migrated .ts test files run with native type stripping.

Assisted-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: bennypowers

packages/dev-server-legacy/package.json

@@ -27,8 +27,8 @@
   "scripts": {
     "build": "tsc",
     "start": "wds --open --config demo/server.config.mjs",
-    "test:node": "node --test --test-force-exit test/**/*.test.ts",
-    "test:watch": "node --test --test-force-exit --watch test/**/*.test.ts"
+    "test:node": "node --experimental-strip-types --test --test-force-exit test/**/*.test.ts",
+    "test:watch": "node --experimental-strip-types --test --test-force-exit --watch test/**/*.test.ts"
   },
   "files": [
     "*.d.ts",