feat: add one-step installer script and enhance README with installation instructions

apps/mac/AIWorkspace/scripts/install.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+INSTALL_LOGIN_ITEM=0
+OPEN_APP=0
+
+for arg in "$@"; do
+  case "$arg" in
+    --start-at-login)
+      INSTALL_LOGIN_ITEM=1
+      ;;
+    --open)
+      OPEN_APP=1
+      ;;
+    *)
+      echo "Unknown argument: $arg" >&2
+      echo "Usage: $0 [--start-at-login] [--open]" >&2
+      exit 1
+      ;;
+  esac
+done
+
+"$SCRIPT_DIR/package-app.sh" --install
+
+if [[ "$INSTALL_LOGIN_ITEM" == "1" ]]; then
+  "$SCRIPT_DIR/install-start-at-login.sh"
+fi
+
+if [[ "$OPEN_APP" == "1" ]]; then
+  open "$HOME/Applications/AIWorkspace.app"
+fi
+
+echo "AI Workspace app install complete."