Implement a CommonJS module loader to replace require()

[cmsj]

NOTE This PR exists as an alternative to #6 without having to use any JavaScriptCore internal API.

Implement a CommonJS-style module loader to replace our naive require() function. Seed a new user's config directory with a package.json and bundler to assist with importing from npm.

These are the steps a new user would take, to make use of this:

1. Install Hammerspoon 2 and launch it. On first run it creates ~/.config/hammerspoon2/ and seeds package.json and bundle.js into it.
2. Install Node.js if not already present - e.g. from nodejs.org or brew install node. This also provides npm and npx.
3. Install the desired package:

cd ~/.config/hammerspoon2
npm install date-fns

4. Bundle it into a single CommonJS file:

npm run bundle

4. This runs bundle.js, which calls npx esbuild (downloaded automatically on first use) and writes lib/date-fns.js.
5. Use it in init.js:

var { format } = require('./lib/date-fns');
console.log(format(new Date(), 'yyyy-MM-dd'));

7. Reload Hammerspoon - either via the menu bar or hs.reload().

Steps 3–4 repeat whenever a new package is added or an existing one is updated. Step 4 is also needed after npm update since it regenerates the bundles from the updated packages.

[greptile-apps]

Greptile Summary

This PR adds a CommonJS module loader and npm bundling workflow for user scripts. The main changes are:

• CommonJS resolution, execution, caching, and JSON support.
• Native file and evaluation bridges for JavaScript modules.
• First-run package and bundler assets in the user config directory.
• Integration tests for module loading and error handling.

Confidence Score: 5/5

This looks safe to merge.

• The malformed JSON path now clears its provisional cache entry before propagating the parse error.
• No distinct blocking failure remains in the updated code paths.

Important Files Changed

Filename	Overview
Hammerspoon 2/Engine/require.js	Adds the CommonJS loader and now removes malformed JSON modules from the cache before rethrowing.
Hammerspoon 2/Engine/JSEngine.swift	Installs the native loader primitives, evaluates the bundled loader, and removes the temporary globals.
Hammerspoon 2/Managers/ManagerManager.swift	Creates a new configuration directory and copies the bundled npm setup files on first launch.
Hammerspoon 2/UserAssets/seed-bundle.js	Adds an esbuild-based script that bundles configured npm dependencies into CommonJS files.
Hammerspoon 2Tests/IntegrationTests/HSRequireIntegrationTests.swift	Adds coverage for exports, path resolution, JSON, caching, cycles, module scope, and error cleanup.

_{Reviews (2): Last reviewed commit: "Make json parsing safer in require.js" | Re-trigger Greptile}

[cmsj]

@greptile