feat: add safe cross-platform upstream updater (#98)

* feat: add safe upstream update scripts

* fix(updater): use portable PowerShell temp path

---------

Co-authored-by: Wibias <37517432+Wibias@users.noreply.github.com>

scripts/update.mjs

@@ -0,0 +1,141 @@
+#!/usr/bin/env node
+/**
+ * Cross-platform entry for `npm run update`.
+ * Windows  -> scripts/update.ps1
+ * Linux/macOS/WSL -> scripts/update.sh
+ */
+import { spawnSync } from 'node:child_process';
+import { existsSync } from 'node:fs';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { platform } from 'node:os';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const root = join(__dirname, '..');
+const args = process.argv.slice(2);
+
+function commandExists(name) {
+  if (platform() === 'win32') {
+    const result = spawnSync('where', [name], { shell: true, stdio: 'pipe' });
+    return result.status === 0;
+  }
+  const result = spawnSync('command', ['-v', name], { shell: true, stdio: 'pipe' });
+  return result.status === 0;
+}
+
+function gitInstallHelp() {
+  const os = platform();
+  if (os === 'win32') {
+    return [
+      '[x] Git is required but was not found on PATH.',
+      '',
+      'Install Git for Windows:',
+      '  https://git-scm.com/download/win',
+      '',
+      'During setup, choose "Git from the command line and also from 3rd-party software".',
+      'Then reopen your terminal and run:  npm run update',
+    ].join('\n');
+  }
+  if (os === 'darwin') {
+    return [
+      '[x] Git is required but was not found on PATH.',
+      '',
+      'Install options:',
+      '  brew install git',
+      '  xcode-select --install',
+      '',
+      'Then run:  npm run update',
+    ].join('\n');
+  }
+  return [
+    '[x] Git is required but was not found on PATH.',
+    '',
+    'Install with your package manager, for example:',
+    '  sudo apt install git        # Debian/Ubuntu',
+    '  sudo dnf install git        # Fedora',
+    '  sudo pacman -S git          # Arch',
+    '',
+    'More: https://git-scm.com/download/linux',
+    '',
+    'Then run:  npm run update',
+  ].join('\n');
+}
+
+function npmInstallHelp() {
+  return [
+    '[x] npm is required but was not found on PATH.',
+    '',
+    'Install Node.js (includes npm): https://nodejs.org/',
+    'Then run:  npm run update',
+  ].join('\n');
+}
+
+function mapArgsForPowerShell(argv) {
+  return argv.flatMap((arg) => {
+    switch (arg) {
+      case '--dry-run':
+        return ['-DryRun'];
+      case '--hard':
+        return ['-Hard'];
+      case '--force':
+        return ['-Force'];
+      case '--keep-backup':
+        return ['-KeepBackup'];
+      default:
+        return [arg];
+    }
+  });
+}
+
+if (!existsSync(join(root, 'package.json'))) {
+  console.error(`[x] Not a T3MP3ST repo (package.json missing): ${root}`);
+  process.exit(1);
+}
+
+if (!commandExists('git')) {
+  console.error(gitInstallHelp());
+  process.exit(1);
+}
+
+if (!commandExists('npm')) {
+  console.error(npmInstallHelp());
+  process.exit(1);
+}
+
+const os = platform();
+const platformLabel = { win32: 'Windows', darwin: 'macOS', linux: 'Linux' }[os] ?? os;
+const scriptName = os === 'win32' ? 'update.ps1' : 'update.sh';
+console.log('\x1b[90m-- Launcher ----------------------------------------\x1b[0m');
+console.log(`  \x1b[36mPlatform\x1b[0m   ${platformLabel}`);
+console.log(`  \x1b[36mDriver\x1b[0m     scripts/${scriptName}`);
+console.log(`  \x1b[36mCommand\x1b[0m    npm run update`);
+console.log('');
+
+let result;
+
+if (os === 'win32') {
+  const ps1 = join(__dirname, 'update.ps1');
+  if (!existsSync(ps1)) {
+    console.error(`[x] Missing updater script: ${ps1}`);
+    process.exit(1);
+  }
+  result = spawnSync(
+    'powershell',
+    ['-NoProfile', '-ExecutionPolicy', 'Bypass', '-File', ps1, ...mapArgsForPowerShell(args)],
+    { cwd: root, stdio: 'inherit' },
+  );
+} else {
+  const sh = join(__dirname, 'update.sh');
+  if (!existsSync(sh)) {
+    console.error(`[x] Missing updater script: ${sh}`);
+    process.exit(1);
+  }
+  result = spawnSync('bash', [sh, ...args], { cwd: root, stdio: 'inherit' });
+}
+
+if (result.error) {
+  console.error(`[x] Failed to start updater: ${result.error.message}`);
+  process.exit(1);
+}
+
+process.exit(result.status ?? 1);