chore(tui): /clean recent perf work — KISS/DRY pass

24 files, -319 LoC. Behaviour preserved, 369/369 tests green.

- hermes-ink caches: shared lruEvict helper for the four parallel LRU
  caches (stringWidth, wrapText, sliceAnsi, lineWidth); touch-on-read
  stays inlined per cache; tightened output.ts skip-slice fast path.
- wheelAccel: trimmed provenance header, collapsed env parsing, ternary
  dispatch in computeWheelStep.
- perfPane: folded ensureLogDir into once-flag, spread-with-overrides
  for fastPath/phases instead of full rebuilds.
- env: extracted truthy() (used 4×).
- virtualHeights: collapsed user/diff/slash height bumps; trail+todos
  estimate.
- useInputHandlers: scrollIdleTimer cleanup on unmount, ?? undefined
  shorthand.
- useMainApp: dropped dead liveTailVisible IIFE and liveProgress
  indirection.
- appLayout, markdown, messageLine, entry: vertical rhythm, dropped
  narration comments, inlined one-shot vars.
- fix: empty catch blocks → /* best-effort */ for no-empty lint.

ui-tui/packages/hermes-ink/src/entry-exports.ts

@@ -1,12 +1,7 @@
 export { default as useStderr } from './hooks/use-stderr.js'
 export { default as useStdout } from './hooks/use-stdout.js'
 export { Ansi } from './ink/Ansi.js'
-export {
-  evictInkCaches,
-  type EvictLevel,
-  type InkCacheSizes,
-  inkCacheSizes
-} from './ink/cache-eviction.js'
+export { evictInkCaches, type EvictLevel, type InkCacheSizes, inkCacheSizes } from './ink/cache-eviction.js'
 export { AlternateScreen } from './ink/components/AlternateScreen.js'
 export { default as Box } from './ink/components/Box.js'
 export { default as Link } from './ink/components/Link.js'
@@ -26,13 +21,9 @@ export { useTabStatus } from './ink/hooks/use-tab-status.js'
 export { useTerminalFocus } from './ink/hooks/use-terminal-focus.js'
 export { useTerminalTitle } from './ink/hooks/use-terminal-title.js'
 export { useTerminalViewport } from './ink/hooks/use-terminal-viewport.js'
-export { isXtermJs } from './ink/terminal.js'
 export { default as measureElement } from './ink/measure-element.js'
-export {
-  resetScrollFastPathStats,
-  scrollFastPathStats,
-  type ScrollFastPathStats
-} from './ink/render-node-to-output.js'
+export { resetScrollFastPathStats, scrollFastPathStats, type ScrollFastPathStats } from './ink/render-node-to-output.js'
 export { createRoot, default as render, renderSync } from './ink/root.js'
 export { stringWidth } from './ink/stringWidth.js'
+export { isXtermJs } from './ink/terminal.js'
 export { default as TextInput, UncontrolledTextInput } from 'ink-text-input'