chore: Add dev.sh tmux script to start server and frontend together

dev.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+# Start server + frontend in dev mode using tmux.
+# Usage: ./dev.sh [session-name]
+#   ./dev.sh        → session "cw"
+#   ./dev.sh myapp  → session "myapp"
+
+set -e
+
+SESSION="${1:-cw}"
+ROOT="$(cd "$(dirname "$0")" && pwd)"
+
+if ! command -v tmux &>/dev/null; then
+  echo "tmux not found. Install with: brew install tmux" >&2
+  exit 1
+fi
+
+if tmux has-session -t "$SESSION" 2>/dev/null; then
+  echo "Session '$SESSION' already running — attaching."
+  exec tmux attach-session -t "$SESSION"
+fi
+
+tmux new-session  -d -s "$SESSION" -n server  -c "$ROOT"
+tmux send-keys    -t "$SESSION:server" "tsx watch apps/server/bin/cw.ts --server" Enter
+
+tmux new-window   -t "$SESSION" -n web -c "$ROOT"
+tmux send-keys    -t "$SESSION:web"    "npm run dev --workspace=apps/web" Enter
+
+tmux select-window -t "$SESSION:server"
+exec tmux attach-session -t "$SESSION"