A 26px strip reserved at the surface bottom: background quad riding
the bg batch, one-line cosmic-text buffer as a second TextArea in
the same prepare pass, right-aligned by measured width. L:C derives
from the optimistic caret (it must not lag a round trip during
typing bursts) and the scroll readout is the TUI's All/Top/Bot/NN%
formula, ported verbatim and pinned.
text_area_bottom() is now the single source for every
bottom-of-text computation: visible-line estimate, text clip
bounds, the minimap height (via a minimap_height() helper), and
the edge-scroll bottom band all subtract the strip through it.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Levi Neuwirth
a962d18d4d