Windowed GUI: wm module, input routing, and the paint app

- Add the wm window-manager facility per ADR 0004: overlapping
  pixel-surface windows, damage-rectangle compositing, WM-drawn title
  bar, focus/minimize/close, and F1-F4 keybindings
- Add gop shadow compositing primitives and vt::repaint_region so the
  console stays layer 0 beneath windows
- Route mouse (absolute coords, press/release edges) and keyboard
  (focus-aware input pump) to the focused window
- Add the rspaint drawing-program crate (pen, 8 colors, clear) and shell
  draw/windows/restore commands
- Extend TaskMsg with AppMouse/Focus/Close and document the design in
  CONTEXT.md + ADR 0004

1 files changed, 8 insertions, 0 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 515158d..76b5a2a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -22,9 +22,17 @@ name = "rsnix"
 version = "0.5.10"
 
 [[package]]
+name = "rspaint"
+version = "0.1.0"
+dependencies = [
+ "rsnix",
+]
+
+[[package]]
 name = "shell"
 version = "0.5.10"
 dependencies = [
  "rsdosedit",
  "rsnix",
+ "rspaint",
 ]