gui: a /dev/draw layer in go, with no cgo and no devdraw

9fans.net/go/draw builds for plan9 but shells out to plan9port's
devdraw, which 9front does not have. This talks to /dev/draw itself:
the protocol is file i/o, so a pure-go client is a few hundred lines
under an already-complete idea.

draw/keyboard.go opens /dev/cons and turns the console raw, as
libdraw's initkeyboard does. Without it rio keeps its line editor on
the window and paints what you type over the drawing.

draw/snarf.go writes /dev/snarf, which is what every other program on
the system means by copy.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/gui/.gitignore b/gui/.gitignore
new file mode 100644
index 0000000..b10d965
--- /dev/null
+++ b/gui/.gitignore
@@ -0,0 +1,3 @@
+# cross-compiled guest binaries
+*.9
+probe/hello-go1.*