numr

I kept leaving the terminal to open a calculator app for things like `20% of 150` or `$100 in euros`, then coming back. Wanted that in the terminal, in a plain file I could keep and edit.

Open `example.numr`. It walks through arithmetic, variables, continuing a line with `+ 10`, currency conversion and units, with totals grouped at the bottom.

The core is a plain library with no I/O, so the TUI, CLI and web build are thin wrappers over the same thing. That's why `numr-cli --server` exists — JSON-RPC over stdin/stdout, so other tools can use it as a calculator backend.

More units and functions, and stabilizing the JSON-RPC protocol so integrations don't break.