revert: app/ → site/ (drhider proves site/ works fine)

site/routes/health_bp.py

@@ -0,0 +1,10 @@
+"""Health probe — обязательно для Штурвала."""
+from flask import Blueprint, jsonify
+from site.config import VERSION
+
+health_bp = Blueprint("health", __name__)
+
+
+@health_bp.route("/health")
+def health():
+    return jsonify({"ok": True, "version": VERSION})