CatGPT 0.1.0

Signed and notarized macOS build (Apple Silicon) — app and DMG both stapled. Open the DMG and drag CatGPT onto the Applications alias; a PDF of the README is inside the DMG and attached below. Before first login, read the login guide (README) — passkeys don't work inside any Electron app; on Google's passkey screen click "Try another way" and use a phone prompt, authenticator code, or SMS.