Save in-progress keysat integration and StartOS 0.4 work

Snapshot of the working tree before cleanup. Captures:
- Keysat licensing: server/license.js, /api/license/* endpoints in
  server/index.js, activation modal in public/index.html, embedded
  Ed25519 issuer key (assets/issuer.pub).
- StartOS 0.4 expansion: setApiKey action, version files v0.1.1
  through v0.1.15, file-models/config.json.ts, manifest updates.
- Self-hosted registry server (startos-registry/).
- Build/deploy scripts (bin/bump-version.sh, bin/deploy.sh, vendored
  yt-dlp binary), .gitignore, .deploy.env.example.
- Recent design docs (KEYSAT_INTEGRATION.md, UPGRADE-DESIGN.md) —
  retained here so they remain recoverable when removed in the
  follow-up cleanup commit.

startos-registry/node_modules/array-flatten/README.md

@@ -0,0 +1,43 @@
+# Array Flatten
+
+[![NPM version][npm-image]][npm-url]
+[![NPM downloads][downloads-image]][downloads-url]
+[![Build status][travis-image]][travis-url]
+[![Test coverage][coveralls-image]][coveralls-url]
+
+> Flatten an array of nested arrays into a single flat array. Accepts an optional depth.
+
+## Installation
+
+```
+npm install array-flatten --save
+```
+
+## Usage
+
+```javascript
+var flatten = require('array-flatten')
+
+flatten([1, [2, [3, [4, [5], 6], 7], 8], 9])
+//=> [1, 2, 3, 4, 5, 6, 7, 8, 9]
+
+flatten([1, [2, [3, [4, [5], 6], 7], 8], 9], 2)
+//=> [1, 2, 3, [4, [5], 6], 7, 8, 9]
+
+(function () {
+  flatten(arguments) //=> [1, 2, 3]
+})(1, [2, 3])
+```
+
+## License
+
+MIT
+
+[npm-image]: https://img.shields.io/npm/v/array-flatten.svg?style=flat
+[npm-url]: https://npmjs.org/package/array-flatten
+[downloads-image]: https://img.shields.io/npm/dm/array-flatten.svg?style=flat
+[downloads-url]: https://npmjs.org/package/array-flatten
+[travis-image]: https://img.shields.io/travis/blakeembrey/array-flatten.svg?style=flat
+[travis-url]: https://travis-ci.org/blakeembrey/array-flatten
+[coveralls-image]: https://img.shields.io/coveralls/blakeembrey/array-flatten.svg?style=flat
+[coveralls-url]: https://coveralls.io/r/blakeembrey/array-flatten?branch=master