Email client like superhuman
Create a .env file in the KeyboardMail directory and add your Google OAuth
client ID. If Google reports that client_secret is missing, add the client
secret from the same OAuth client:
GMAIL_CLIENT_ID=your-client-id.apps.googleusercontent.com
GMAIL_CLIENT_SECRET=your-client-secretThe app loads .env from the current directory or its parent directories.
Environment variables take precedence over values in .env. Keep .env local;
it is ignored by Git. Then start the app from VS Code or run swift run from
KeyboardMail. Sign-in opens your system browser and uses Google's Desktop
OAuth loopback redirect with PKCE; create a Desktop app OAuth client in
Google Cloud Console. Desktop clients usually do not require a client secret;
only configure one if your Google OAuth client requires it.