e2e: smoke + state specs, CI-only against isolated dind stack

playwright.config.ts mirrors Flight-Ops shape (remote browser default ws://192.168.1.4:3000/,
PW_REMOTE_BROWSER=0 local, E2E_BASE_URL/E2E_DEPLOY_CMD optional). smoke.spec.ts: landing
page + scificn components + /api/version. state.spec.ts: mid-run docker compose restart
via E2E_COMPOSE_ARGS, re-asserts the app serves (no auth — single player by design).

e2e/ci-diagnostics.ts

@@ -0,0 +1,36 @@
+// CI-only connectivity diagnostics (globalSetup runs after the e2e stack is ready).
+// Evidence for the Chromium ERR_SSL_PROTOCOL_ERROR hunt: compares node-side resolution/HTTP
+// against Chromium's own navigation, hostname vs static IP. Never fails the run.
+import { promises as dnsPromises } from 'node:dns';
+import { chromium } from '@playwright/test';
+
+export default async function ciDiagnostics() {
+  if (process.env.PW_REMOTE_BROWSER !== '0') return; // local runs: no-op
+  const base = process.env.E2E_BASE_URL ?? '';
+  try {
+    console.log('[diag] node resolve4(app):', JSON.stringify(await dnsPromises.resolve4('app').catch((e) => `failed: ${e.code}`)));
+    try {
+      const r = await fetch(`${base}/api/version`);
+      console.log('[diag] node fetch', base, '->', r.status, JSON.stringify(await r.json().catch(() => null)));
+    } catch (e) {
+      console.log('[diag] node fetch failed:', String(e));
+    }
+    const browser = await chromium.launch();
+    try {
+      for (const url of ['http://app:3000/', base]) {
+        const page = await (await browser.newContext()).newPage();
+        try {
+          await page.goto(url, { timeout: 15_000 });
+          console.log('[diag] chromium goto', url, '-> OK, title:', await page.title().catch(() => '?'));
+        } catch (e) {
+          console.log('[diag] chromium goto', url, '-> FAILED:', String(e).split('\n')[0]);
+        }
+        await page.context().close();
+      }
+    } finally {
+      await browser.close();
+    }
+  } catch (e) {
+    console.log('[diag] diagnostics error (non-fatal):', String(e));
+  }
+}