fix(core,tooling): keep the harness's own ports out of the Agent's environment and off the dev server (#100)

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Co-authored-by: J.Li <jl2388@cam.ac.uk>

packages/server/package.json

@@ -25,7 +25,7 @@
     "node": ">=24"
   },
   "scripts": {
-    "dev": "node ../../scripts/dev-prebuild.mjs && node ../../scripts/run-with-env.mjs PENGUIN_HOME=~/.penguin/dev-data -- tsx watch src/index.ts",
+    "dev": "node ../../scripts/dev-prebuild.mjs && node ../../scripts/run-with-env.mjs PENGUIN_HOME=~/.penguin/dev-data PORT=7368 -- tsx watch src/index.ts",
     "start": "node --disable-warning=ExperimentalWarning dist/index.js",
     "typecheck": "tsc --noEmit -p tsconfig.json",
     "test": "vitest run --passWithNoTests",