fix: skip postinstall/prepare scripts when installed as npm package

[simongdavies]

The postinstall and prepare hooks reference scripts in scripts/ which are not included in the published npm package (files: ['dist/'] only). This caused 'npm install -g @hyperlight-dev/hyperagent' to fail with MODULE_NOT_FOUND.

Use '[ ! -f script ] || command' pattern so hooks skip gracefully when scripts don't exist (published package) but still fail loudly when they do exist and error (dev context).

[Copilot]

Pull request overview

Adjust npm lifecycle hooks so global installs from the published package (which ships only dist/) don’t fail when scripts/* is absent, while preserving the existing behavior in a source/dev checkout.

Changes:

• Update prepare to no-op when scripts/build-modules.js is not present.
• Update postinstall to no-op when scripts/patch-vscode-jsonrpc.js is not present, otherwise run the existing patch + runtime check.

[Copilot]

The new prepare/postinstall guards use POSIX [ ... ] tests and subshell syntax, which will fail (or behave incorrectly) when npm runs scripts under cmd.exe on Windows. If Windows installs are expected now or in the future, consider switching to a Node-based existence check (e.g., a tiny JS entrypoint in dist/ that checks fs.existsSync(...) before running the real script) so the hooks are cross-platform while still skipping cleanly in the published tarball.

Suggested change

	"prepare": "[ ! -f scripts/build-modules.js ] || npm run build:modules",
	"postinstall": "[ ! -f scripts/patch-vscode-jsonrpc.js ] || (node scripts/patch-vscode-jsonrpc.js && node scripts/check-native-runtime.js)"
	"prepare": "node -e \"const fs = require('fs'); const { spawnSync } = require('child_process'); if (!fs.existsSync('scripts/build-modules.js')) process.exit(0); const npmCmd = process.platform === 'win32' ? 'npm.cmd' : 'npm'; const result = spawnSync(npmCmd, ['run', 'build:modules'], { stdio: 'inherit' }); process.exit(result.status == null ? 0 : result.status);\"",
	"postinstall": "node -e \"const fs = require('fs'); const { spawnSync } = require('child_process'); if (!fs.existsSync('scripts/patch-vscode-jsonrpc.js')) process.exit(0); const nodePath = process.execPath; let r = spawnSync(nodePath, ['scripts/patch-vscode-jsonrpc.js'], { stdio: 'inherit' }); if (r.status) process.exit(r.status); r = spawnSync(nodePath, ['scripts/check-native-runtime.js'], { stdio: 'inherit' }); process.exit(r.status == null ? 0 : r.status);\""