Summary

• Modern rewrite of the abandoned RisingStack/koa-prerender package
• Updated from Koa v1 generator functions (function*, yield) to Koa v2+ async middleware (async (ctx, next))
• Replaced deprecated request and thunkify-wrap packages with built-in fetch (Node 18+) — zero dependencies
• Updated bot list with modern crawlers (GPTBot, ClaudeBot, Amazonbot, Perplexity, etc.)

Test plan

• 5 smoke tests covering: browser passthrough, bot interception, static asset bypass, _escaped_fragment_, fetch error fallback
• Run with npm test inside prerender-koa/