Research Scry terminal backends

[naveenadi]

Part of #1

Question

Which maintained, permissively licensed terminal backend can Scry call through a small LuaJIT FFI wrapper while providing termbox-compatible primitives on Linux, macOS, and Windows? Resolve its supported capabilities, build/link prerequisites, licence, portability limitations, and how it affects the mandatory size/startup targets.

[naveenadi]

Resolution

Use termbox2 (MIT, single-header, libc-only) as the Unix terminal backend behind a thin src/ui/tui.lua FFI wrapper.

Windows is not upstream-ready (PR termbox/termbox2#123 still open). Plan a Scry-owned Win32/VT backend implementing the same wrapper API rather than adopting notcurses or ncurses.

Size/startup impact of termbox2 is expected to be small versus LuaJIT + DB clients; measure in the runtime prototype. Rejected notcurses (heavy, terminfo-coupled) and original termbox (superseded).

Context pointer

• Branch: research/scry-terminal-backends @ 248bce6
• Notes: docs/research/scry-terminal-backends.md
• https://github.com/naveenadi/scry/blob/research/scry-terminal-backends/docs/research/scry-terminal-backends.md

[naveenadi]

Resolved: termbox2 on Unix; separate Windows backend path. See resolution comment.