Consolidate engine docs and naming

scripts/run-engine.js

@@ -0,0 +1,51 @@
+#!/usr/bin/env node
+
+const { spawnSync } = require('child_process');
+const fs = require('fs');
+const path = require('path');
+
+function loadDotEnv(filePath) {
+  if (!fs.existsSync(filePath)) return;
+  const lines = fs.readFileSync(filePath, 'utf8').split(/\r?\n/);
+  for (const line of lines) {
+    const trimmed = line.trim();
+    if (!trimmed || trimmed.startsWith('#')) continue;
+    const match = trimmed.match(/^([A-Za-z_][A-Za-z0-9_]*)=(.*)$/);
+    if (!match) continue;
+    const [, key, rawValue] = match;
+    if (process.env[key] != null) continue;
+    process.env[key] = rawValue.replace(/^["']|["']$/g, '');
+  }
+}
+
+const projectRoot = path.resolve(__dirname, '..');
+loadDotEnv(path.join(projectRoot, '.env'));
+
+const mode = process.argv[2] || 'dev';
+const engine = String(process.env.DEFAULT_GAME_ENGINE || process.env.GAME_ENGINE || 'ink')
+  .trim()
+  .toLowerCase();
+const allowedModes = new Set(['dev', 'start']);
+const allowedEngines = new Set(['ink', 'yaml', 'zcode']);
+
+if (!allowedModes.has(mode)) {
+  console.error(`Unsupported run mode "${mode}". Use "dev" or "start".`);
+  process.exit(1);
+}
+
+if (!allowedEngines.has(engine)) {
+  console.error(`Unsupported DEFAULT_GAME_ENGINE "${engine}". Use "ink", "yaml", or "zcode".`);
+  process.exit(1);
+}
+
+const npmCommand = process.platform === 'win32' ? 'npm.cmd' : 'npm';
+const script = `${mode}:${engine}`;
+console.log(`[run-engine] DEFAULT_GAME_ENGINE=${engine}; running npm run ${script}`);
+
+const result = spawnSync(npmCommand, ['run', script], {
+  cwd: projectRoot,
+  env: process.env,
+  stdio: 'inherit',
+});
+
+process.exit(result.status == null ? 1 : result.status);