fix(runner): Dev-Neustart bei geänderten Variablen, Liveness-Prüfung, npm-ci-Fallback

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

runner/test/proxy.test.js

@@ -221,3 +221,14 @@ test('WebSocket-Daten touchen höchstens einmal pro Minute', async () => {
     }, { now: () => clock.t });
   } finally { t.srv.closeAllConnections?.(); await new Promise((r) => t.srv.close(r)); }
 });
+
+test('I7: Upstream ECONNREFUSED ⇒ dev.markDead + 502', async () => {
+  const dead = [];
+  const srv = http.createServer(); await new Promise((r) => srv.listen(0, '127.0.0.1', r));
+  const port = srv.address().port; await new Promise((r) => srv.close(r)); // Port ist jetzt zu
+  await withProxy({ wake: async () => ({ state: 'online', target: `http://127.0.0.1:${port}` }), markDead: async (s) => { dead.push(s); } }, async ({ port: p }) => {
+    const { res } = await get(p, 'demo.project.webklar.com');
+    assert.equal(res.statusCode, 502);
+    assert.deepEqual(dead, ['demo']);
+  });
+});