Inline mode leaves stale composer rows ("ghosts") when the terminal grows taller

Summary

In inline mode (WithInlineHeight), resizing the terminal window taller than the viewport height leaves stale composer rows above the new viewport — the old input band stays on screen as "ghosts" until it scrolls away.

Reproduction

1. Run a go-tui app in inline mode (e.g. a bottom-pinned input widget).
2. Let some content print above the widget so the viewport is at the bottom of a N-row terminal.
3. Grow the terminal by more than the inline height (drag the window edge).
4. The old widget rows (input line etc.) remain visible above the newly positioned widget.

Root cause

On a resize, renderInline's full redraw does SetCursor(0, inlineStartRow); ClearToEnd() — it only clears from the new viewport start row downward. When the terminal grows, the old viewport rows lie above the new start row and are never erased. Each growth step leaves another stale band, so dragging produces many ghosts.

Additionally, renderFrame only re-syncs inline geometry when the buffer width changes; when only the height changes (and the ResizeEvent is still queued), the composer can be drawn at a stale row for a frame.

Proposed fix

• Clear from min(prevInlineStartRow, inlineStartRow) (the union of old/new viewport top rows) before repainting.
• Re-sync inline geometry against the live terminal size on every frame, forcing a full redraw whenever it differs.

This mirrors how Codex (openai/codex) handles inline viewports on resize: clear_after_position(min(old.y, new.y)) then full repaint.

I have a fix + tests ready in PR #120.