Keystone v1.0.0

First release. Keystone is an Electron-based performance workbench: a controllable browser window with device emulation, network throttling, and cache/cookie control, paired with a built-in reporting suite so you don't need to hop between separate tools to test a page.

Included in this release:

• Device presets (phones, tablets, monitors) and custom aspect ratios
• Network throttling (Fast 3G, Slow 3G, offline, custom Mbps)
• Cache, DNS, and cookie control between page loads
• JavaScript and CSS toggles, X-Ray mode, dark mode override
• Screenshot capture and native DevTools access
• Reports panel with seven tabs: Summary, Full Report, Diagnostics (cold vs warm load comparison), Security (header checks), Coverage (unused JS/CSS), Baseline (multi-URL comparison), and Runtime (live memory and main-thread monitor)

Reports run on Lighthouse under the hood, using a bundled headless Chromium instance. No account, no external server, no request limits.

Currently built and tested on macOS only. Windows and Linux should run but haven't been verified end-to-end yet. See the README for setup instructions and known gaps.