feat(core,tooling): Windows support — shell selection, install.ps1, win-x64 release package, Windows CI (#79)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

package.json

@@ -15,7 +15,7 @@
     "test:e2e": "pnpm --filter @prismshadow/penguin-core test:e2e",
     "build": "pnpm -r build && pnpm link:cli",
     "link:cli": "pnpm --dir packages/cli link --global || echo '[link:cli] pnpm global directory not configured; skipping the global penguin link (run pnpm setup once first)'",
-    "penguin": "PENGUIN_HOME=\"${PENGUIN_HOME:-$HOME/.penguin/dev-data}\" tsx packages/cli/src/index.ts",
+    "penguin": "node scripts/run-with-env.mjs PENGUIN_HOME=~/.penguin/dev-data -- tsx packages/cli/src/index.ts",
     "dev": "concurrently -n server,web -c cyan,magenta \"pnpm dev:server\" \"pnpm dev:web\"",
     "dev:server": "pnpm --filter @prismshadow/penguin-server dev",
     "dev:web": "node scripts/dev-prebuild.mjs && pnpm --filter @prismshadow/penguin-web dev",