Fixes (#4458)

Fixing the "? for shortcuts"

- Only show the hint when composer is empty
- Don't reset footer on new task updates
- Reorder the elements
- Align the "?" and "/" with overlay on and off

Based on #4364

codex-rs/tui/src/ui_consts.rs

@@ -8,3 +8,4 @@
 /// - Status indicator lines begin with this many spaces for alignment.
 /// - User history lines account for this many columns (e.g., "▌ ") when wrapping.
 pub(crate) const LIVE_PREFIX_COLS: u16 = 2;
+pub(crate) const FOOTER_INDENT_COLS: usize = LIVE_PREFIX_COLS as usize;