feat: add Hono API with JWT authentication

- Implement REST API using Hono framework with token-based auth
- Add JWT middleware for scope-based access control
- Create version endpoints: launcher, downloader, patches, server
- Add account lookup endpoints (by UUID or username)
- Fetch server software with signed URLs and full version data
- Add token signing utility script for testing
- Support configurable account UUID for game session creation
- Integrate API server with existing module system

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

scripts/sign-token.ts

@@ -0,0 +1,34 @@
+import jwt from 'jsonwebtoken'
+import process from 'node:process'
+
+const args = process.argv.slice(2)
+let scopes = 'admin'
+let expirationHours = 24
+
+for (let i = 0; i < args.length; i++) {
+  if (args[i] === '--scope' && args[i + 1]) {
+    scopes = args[i + 1]
+    i++
+  }
+  else if (args[i] === '--exp' && args[i + 1]) {
+    const expStr = args[i + 1]
+    const match = expStr.match(/^(\d+)h?$/)
+    if (match) {
+      expirationHours = parseInt(match[1], 10)
+    }
+    i++
+  }
+}
+
+const jwtSecret = process.env.JWT_SECRET || 'your-secret-key'
+
+const payload = {
+  scope: scopes,
+  sub: 'test-client',
+  iat: Math.floor(Date.now() / 1000),
+  exp: Math.floor(Date.now() / 1000) + (expirationHours * 3600),
+}
+
+const token = jwt.sign(payload, jwtSecret, { algorithm: 'HS256' })
+
+console.log(token)