fix: serve test-api.html at /docs on Vercel and Worker deployments

Update api/relay.ts (Vercel entry point) and src/worker.ts (Cloudflare
Workers entry point) to serve the interactive API test console at /docs
and /test, replacing the old inline docs page.

api/relay.ts uses Bun's HTML import (bundled inline at build time)
since filesystem access is unavailable in Vercel serverless runtime.

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

src/worker.ts

@@ -386,7 +386,14 @@ export default {
 		const url = new URL(req.url);
 
 		if (url.pathname === "/health") return handleHealth();
-		if (url.pathname === "/docs") return handleDocs();
+		if (url.pathname === "/docs" || url.pathname === "/test") {
+			const file = Bun.file("public/test-api.html");
+			const exists = await file.exists();
+			return new Response(exists ? file : "Not found", {
+				status: exists ? 200 : 404,
+				headers: { "Content-Type": "text/html; charset=utf-8" },
+			});
+		}
 		if (
 			url.pathname === "/" &&
 			req.method === "GET" &&