FuJacob/cotabby — reverse-engineered prompt

Build me a Mac menu bar app called Cotabby that gives me AI autocomplete anywhere I type on my Mac. I want gray ghost text to appear inline near the cursor in most text fields, then I can press Tab to accept the next word, press backtick to accept the whole suggestion, or just keep typing to ignore it. Please also include emoji completion from things like :rocket:, simple slash macros for quick math, unit and currency conversion, dates, and random values, plus a one key typo fix.

The big requirement is privacy. Everything should run locally on my Mac, with no account, no cloud, no telemetry, and no saving what I type during normal use. Let me choose between using Apple Intelligence when available or downloading a small local model inside the app. Add a clean settings screen for engine choice, model downloads, shortcut rebinding, and acceptance mode. It should guide me through Accessibility, Input Monitoring, and optional Screen Recording permissions, and never read secure password fields. Look up current Mac docs if you need to.