refactor(tui): /clean pass on tui-polish — data tables, tighter title

- normalizeStatusBar: replace Set + early-returns + cast with a single
  alias lookup table. Handles legacy `false`, trims/lowercases strings,
  maps `on` → `top` in one pass. One expression, no `as` hacks.
- Tab title block: drop the narrative comment, fold
  blockedOnInput/titleStatus/cwdTag/terminalTitle into inline expressions
  inside useTerminalTitle. Avoids shadowing the outer `cwd`.
- tui_gateway statusbar set branch: read `display` once instead of
  `cfg0.get("display")` twice.

ui-tui/src/app/useConfigSync.ts

@@ -14,23 +14,16 @@ import type { StatusBarMode } from './interfaces.js'
 import { turnController } from './turnController.js'
 import { patchUiState } from './uiStore.js'
 
-const STATUSBAR_MODES = new Set<StatusBarMode>(['bottom', 'off', 'top'])
-
-export const normalizeStatusBar = (raw: unknown): StatusBarMode => {
-  if (raw === false) {
-    return 'off'
-  }
-
-  if (typeof raw !== 'string') {
-    return 'top'
-  }
-
-  const v = raw.trim().toLowerCase()
-  const mode = (v === 'on' ? 'top' : v) as StatusBarMode
-
-  return STATUSBAR_MODES.has(mode) ? mode : 'top'
+const STATUSBAR_ALIAS: Record<string, StatusBarMode> = {
+  bottom: 'bottom',
+  off: 'off',
+  on: 'top',
+  top: 'top'
 }
 
+export const normalizeStatusBar = (raw: unknown): StatusBarMode =>
+  raw === false ? 'off' : typeof raw === 'string' ? STATUSBAR_ALIAS[raw.trim().toLowerCase()] ?? 'top' : 'top'
+
 const MTIME_POLL_MS = 5000
 
 const quietRpc = async <T extends Record<string, any> = Record<string, any>>(