Tool messages show as toasts, the card status line is gone (t27)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/DESIGN.md

@@ -235,6 +235,12 @@ above, including:
   the bag; Ctrl+click a bag name adds it to the blow mix and Ctrl+right-click to pick-up; the menu
   is one line per material because the first version was too large.
 
+- **Tool messages are toasts (t27, 2026-10-24).** Every tool's messages ("Nothing selected", "Out
+  of reach.", "Nothing to use there.") show as toasts at the top of the screen, and the red line in
+  the tool card is gone. The owner asked for it for the vacuum and chose every tool. Errors have a
+  red edge, info a patina one. A message that repeats every tick while a button is held keeps one
+  toast alive instead of stacking more.
+
 - **Pick up what you click, blow out what's in hand (t20, 2026-10-24).** Replaces t16's pick-up
   marks and the vacuum menu; the owner wanted something simpler and more intuitive. A left drag
   takes only the material it starts on (or the first loose grain it reaches); Shift takes