Add demo.sh — shell wrapper for raw terminal mode

Raw terminal mode must be set by the parent process (the shell),
not from inside SBCL.  sb-ext:run-program subprocesses cannot
reliably access the controlling terminal for stty operations.
./demo.sh sets raw mode via stty, runs sbcl --script demo.lisp,
and restores terminal state on exit (EXIT, INT, TERM).

demo.lisp no longer calls with-raw-terminal — it assumes the
calling shell has already set raw mode.

demo

@@ -1,20 +0,0 @@
-#!/bin/sh
-# cl-tty demo launcher
-# Sets raw terminal mode, runs the demo, restores terminal on exit.
-# This is needed because SBCL's --script mode + run-program combo
-# can't reliably set raw mode from inside the Lisp process.
-
-SAVED=$(stty -g 2>/dev/null)
-if [ -z "$SAVED" ]; then
-    echo "ERROR: Not running in a real terminal." >&2
-    echo "       Try: sbcl --script demo.lisp" >&2
-    exit 1
-fi
-
-cleanup() {
-    stty "$SAVED" 2>/dev/null
-}
-trap cleanup EXIT INT TERM
-
-stty raw -echo -isig -icanon min 1 time 0 2>/dev/null
-sbcl --script "$(dirname "$0")/demo.lisp"

demo.lisp

@@ -1,9 +1,5 @@
 ;;; demo.lisp — cl-tty interactive demo
 ;;; Run: sbcl --script demo.lisp
-;;;
-;;; Demonstrates: backend detection, raw terminal mode, key/mouse input,
-;;; layout engine, component rendering pipeline, framebuffer diff flush,
-;;; text-input, textarea, select, dialog, scrollbox, tabbar.
 
 ;; Load cl-tty directly via ASDF (no Quicklisp dependency needed —
 ;; sb-posix is built into SBCL, no external libraries required).
@@ -124,10 +120,8 @@
      t)))
 
 (defun run-demo ()
-  "Run the demo.  Assumes raw terminal mode is already set by the
-shell wrapper (./demo) or by running:
-  stty raw -echo -isig -icanon min 1 time 0
-  sbcl --script demo.lisp"
+  "Run the demo.  Raw terminal mode should already be set by the
+./demo.sh shell wrapper."
   (init-app-state)
   (let* ((backend (detect-backend))
          (w 80) (h 24))

demo.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+# cl-tty demo launcher
+# Sets raw terminal mode before starting SBCL, restores on exit.
+# Raw mode is needed so individual keystrokes are captured instead
+# of being line-buffered and echoed by the terminal driver.
+
+SAVED=$(stty -g 2>/dev/null)
+if [ -z "$SAVED" ]; then
+    echo "ERROR: Not running in a real terminal." >&2
+    exit 1
+fi
+
+cleanup() { stty "$SAVED" 2>/dev/null; }
+trap cleanup EXIT INT TERM
+
+stty raw -echo -isig -icanon min 1 time 0 2>/dev/null
+sbcl --script "$(dirname "$0")/demo.lisp"