Wrap toast bodies, slim the dismiss hint, and stop flicker

Toasts now render three content rows with word-wrapped bodies. The
in-toast "Ctrl-N · N more" hint is replaced by a short
"Ctrl-N · dismiss" entry on the status strip that only appears
while a notification is live.

The box stops flickering while the focused child repaints its TUI:
the overlay is stitched onto the per-chunk PTY write under outMu
and bracketed by DECSET 2026 so supporting terminals buffer the
child's redraw and the box paint into a single frame.

CHANGELOG.md

@@ -6,6 +6,22 @@ loosely follows [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+### Changed
+- Toast notifications now reserve three content rows and word-wrap
+  the message body inside the box, replacing the previous
+  single-line+ellipsis layout. The `Ctrl-N · N more` inline hint is
+  gone; instead the host status strip surfaces a `Ctrl-N · dismiss`
+  hint, shown only while a notification is on screen so the chord
+  doesn't advertise itself when it has nothing to dismiss.
+
+### Fixed
+- Toast box no longer flickers / half-erases while the focused
+  child (claude, codex, opencode, etc.) repaints its TUI. The
+  overlay is now stitched onto the end of the per-chunk PTY write
+  under `outMu`, and wrapped in DECSET 2026 (synchronized output)
+  brackets so terminals that support it batch the child's redraw +
+  the box paint into a single frame instead of racing cell-by-cell.
+
 ## [0.0.5] - 2026-05-15
 
 ### Changed