perf: keep the TUI off the status line render path

[durandom]

Problem

Claude Code re-runs the status line command every couple of seconds for as long as a session is open, so this binary's module load time is paid continuously rather than once at startup.

src/ccstatusline.ts imports runTUI statically:

import { runTUI } from './tui';

That pulls ink, React and yoga-layout into the render path even though rendering never touches any of them — they are only needed for the interactive config editor.

What I tried first, and why it wasn't enough

Making the import dynamic on its own changes nothing measurable: bun build --outfile cannot code-split, so the whole graph still ends up in one file and still gets parsed on every render. I measured 255 ms vs 250 ms, i.e. noise.

The win only appears when the build actually splits. --splitting --format=esm --outdir=dist moves the TUI into its own chunk and shrinks the entry from 3.34 MB to 21 KB.

Result

M-series Mac, 20 runs per data point, a real Claude Code payload piped to stdin:

	ms/render
before	238, 237, 238
after	226, 222, 220

About 7%. Modest, but it is paid on every render for the whole session, and the rendered output is byte-identical (diff on the ANSI output).

Verification

• bun run lint (tsc + eslint) clean.
• Rendered output byte-identical before/after.
• Interactive TUI smoke-tested under a pty: same first frame, no module resolution errors.
• Built output runs under node as well as bun.

The non-obvious part

scripts/replace-version.ts had to change too. With splitting, the __PACKAGE_VERSION__ placeholder lands in a chunk rather than in dist/ccstatusline.js, so patching only the entry would have silently shipped an unreplaced placeholder. It now patches every emitted script and exits non-zero if it finds none, so this cannot regress quietly.

Packaging is unaffected: files is already dist/, and bin/main/exports keep pointing at dist/ccstatusline.js.

https://claude.ai/code/session_01Jy7HKv8er6ZiodbjFeped2