fix(tui): /statusbar top = inline above input, not row 0 of the screen

'top' and 'bottom' are positions relative to the input row, not the alt
screen viewport:

- top (default) → inline above the input, where the bar originally lived
  (what 'on' used to mean)
- bottom → below the input, pinned to the last row
- off → hidden

Drops the literal top-of-screen placement; 'on' is kept as a backward-
compat alias that resolves to 'top' at both the config layer
(normalizeStatusBar, _coerce_statusbar) and the slash command.

ui-tui/src/app/useConfigSync.ts

@@ -14,17 +14,18 @@ import type { StatusBarMode } from './interfaces.js'
 import { turnController } from './turnController.js'
 import { patchUiState } from './uiStore.js'
 
-const STATUSBAR_MODES = new Set<StatusBarMode>(['bottom', 'off', 'on', 'top'])
+const STATUSBAR_MODES = new Set<StatusBarMode>(['bottom', 'off', 'top'])
 
-// Legacy configs stored tui_statusbar as a bool; new configs write a string
-// ('on' | 'off' | 'bottom' | 'top'). Coerce both shapes so existing users
-// keep their preference without manual migration.
+// Legacy configs stored tui_statusbar as a bool; the short-lived 4-mode
+// variant wrote 'on'. Both map to 'top' (inline above the input) — the
+// original feature's default — so users keep their preference without
+// manual migration.
 export const normalizeStatusBar = (raw: unknown): StatusBarMode => {
   if (raw === false) return 'off'
-  if (raw === true || raw == null) return 'on'
+  if (raw === true || raw == null || raw === 'on') return 'top'
   if (typeof raw === 'string' && STATUSBAR_MODES.has(raw as StatusBarMode)) return raw as StatusBarMode
 
-  return 'on'
+  return 'top'
 }
 
 const MTIME_POLL_MS = 5000