feat: add Atlas native app UX overhaul

scripts/atlas/verify-app-launch.sh

@@ -0,0 +1,35 @@
+#!/bin/bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "$0")/../.." && pwd)"
+APP_PATH="${APP_PATH:-$HOME/Applications/Atlas for Mac.app}"
+BIN_PATH="$APP_PATH/Contents/MacOS/Atlas for Mac"
+STATE_DIR="${STATE_DIR:-$ROOT_DIR/.build/atlas-launch-state}"
+
+if [[ ! -x "$BIN_PATH" ]]; then
+  echo "App binary not found: $BIN_PATH" >&2
+  exit 1
+fi
+
+mkdir -p "$STATE_DIR"
+ATLAS_STATE_DIR="$STATE_DIR" "$BIN_PATH" >/tmp/atlas-launch.log 2>&1 &
+pid=$!
+
+cleanup() {
+  if kill -0 "$pid" >/dev/null 2>&1; then
+    kill "$pid" >/dev/null 2>&1 || true
+    wait "$pid" >/dev/null 2>&1 || true
+  fi
+}
+trap cleanup EXIT
+
+sleep 3
+
+if ! kill -0 "$pid" >/dev/null 2>&1; then
+  echo "Atlas app exited immediately; see /tmp/atlas-launch.log" >&2
+  cat /tmp/atlas-launch.log >&2 || true
+  exit 1
+fi
+
+echo "App launch smoke test succeeded"
+echo "PID: $pid"