Build, bundle and untouched directories (T12): de-cluttering the control plane UI

Run at verification on 2026-10-20.

Build

cd ui && bun run build
$ tsc --noEmit && vite build
dist/index.html                   2.05 kB │ gzip:   0.95 kB
dist/assets/index-DGFyk9GC.css   24.42 kB │ gzip:   5.76 kB
dist/assets/index-DHxDxucx.js   337.16 kB │ gzip: 102.35 kB │ map: 1,441.04 kB
✓ built in 1.29s

Bundle against the branch point (NFR: removal must not grow it)

Asset	20.5.1 (branch point)	This branch	Change
JS	341 685 B	337 157 B	−4 528 B
CSS	24 469 B	24 421 B	−48 B

The CSS first grew by a few hundred bytes from new utility classes on the popover and the header; the summary's marker, a separator span and five utilities were replaced by classes the app already used (commit 46a85e2), which brought it under the baseline.

Re-run after self-review round 1 (dead code removed: the panel column, the open-panel button path, three icons, a dead composer prop): bun run build clean; JS 336 728 B, CSS 24 350 B — smaller again.

Re-run after the critic round (the empty-rail sentence restored in the header, the popover measured on open, the pointer's aria-current): bun run build clean; JS 336 965 B, CSS 24 350 B.

Untouched directories (R5.1)

git diff --stat origin/main -- ui/src/api ui/src/state ui/src/demo
(empty)

No dependency was added: ui/package.json and ui/bun.lock are unchanged; Playwright for the screenshot run was installed without saving, as ui/scripts/screenshots.mjs documents.