Replace the floating approval modal (which blanked the whole UI) with an
opencode-style band that takes the input bar's slot while a gate is
pending: tool/tier/risk header above a side-by-side old|new diff, with
the session output and event stream still visible above it. The band
height adapts to the diff length.
Add a unified-diff parser that aligns removals/additions into split rows
(blank left cell for a create, blank right for a delete) and a
two-column renderer shared by the band preview and the ^x fullscreen
view. Wire plain a/r to approve/reject to match the advertised keys.
kami
03ccac76c7