test: add golden-path replay demo

package.json

@@ -10,7 +10,8 @@
     "test:unit": "jest",
     "test:demo": "start-server-and-test \"npm run serve-demo -- --port 4173\" http://127.0.0.1:4173/demo \"npx playwright test --config=playwright.config.ts --reporter=list,html,junit\"",
     "test:replay": "jest tests/replay/replay.spec.js",
-    "lint:md": "remark .opencode/command/*.md --quiet --frail"
+    "lint:md": "remark .opencode/command/*.md --quiet --frail",
+    "test:golden": "node tests/golden-path/run-golden.js"
   },
   "devDependencies": {
     "@playwright/test": "^1.40.0",

tests/golden-path/run-golden.js

@@ -0,0 +1,79 @@
+#!/usr/bin/env node
+const { execFile } = require('child_process');
+const fs = require('fs');
+const path = require('path');
+
+const STORY_PATH = path.resolve(__dirname, '..', '..', 'web', 'stories', 'demo.ink');
+const SCRIPT_PATH = path.resolve(__dirname, 'scripts', 'demo.golden.json');
+const REPLAY_SCRIPT = path.resolve(__dirname, '..', '..', 'scripts', 'replay.js');
+const TIMEOUT_MS = 30_000;
+
+function ensurePaths() {
+  if (!fs.existsSync(STORY_PATH)) {
+    throw new Error(`Story not found at ${STORY_PATH}`);
+  }
+  if (!fs.existsSync(SCRIPT_PATH)) {
+    throw new Error(`Golden script not found at ${SCRIPT_PATH}`);
+  }
+  if (!fs.existsSync(REPLAY_SCRIPT)) {
+    throw new Error(`Replay harness not found at ${REPLAY_SCRIPT}`);
+  }
+}
+
+function writeFailureLog(output) {
+  try {
+    const dir = path.join(__dirname, '..', '..', 'test-results', 'replay', String(Date.now()));
+    fs.mkdirSync(dir, { recursive: true });
+    const logPath = path.join(dir, 'logs.txt');
+    fs.writeFileSync(logPath, output, 'utf8');
+    return logPath;
+  } catch (err) {
+    return null;
+  }
+}
+
+function run() {
+  ensurePaths();
+  const args = ['--story', STORY_PATH, '--script', SCRIPT_PATH];
+  const child = execFile('node', [REPLAY_SCRIPT, ...args], { timeout: TIMEOUT_MS }, (error, stdout, stderr) => {
+    if (error) {
+      const combined = `stdout:\n${stdout}\n\nstderr:\n${stderr}\n\nerror:${error.message}`;
+      const logPath = writeFailureLog(combined);
+      if (logPath) {
+        console.error(`Golden-path replay failed; logs saved to ${logPath}`);
+      } else {
+        console.error('Golden-path replay failed; unable to save logs');
+      }
+      console.error(combined);
+      process.exitCode = error.code || 1;
+      return;
+    }
+    process.stdout.write(stdout);
+  });
+
+  child.on('error', (err) => {
+    const logPath = writeFailureLog(`spawn error: ${err.message}`);
+    if (logPath) {
+      console.error(`Golden-path replay spawn failed; logs saved to ${logPath}`);
+    } else {
+      console.error('Golden-path replay spawn failed; unable to save logs');
+    }
+    console.error(err);
+    process.exit(1);
+  });
+}
+
+if (require.main === module) {
+  try {
+    run();
+  } catch (err) {
+    const logPath = writeFailureLog(`setup error: ${err.message}`);
+    if (logPath) {
+      console.error(`Golden-path replay setup failed; logs saved to ${logPath}`);
+    }
+    console.error(err.message);
+    process.exit(1);
+  }
+}
+
+module.exports = { run };

tests/golden-path/scripts/demo.golden.json

@@ -0,0 +1 @@
+[0,0,0,0]