v0.4.0: Remove free tier, add public demo endpoint with watermark

- Remove free account signup flow entirely
- Add POST /v1/demo/html and /v1/demo/markdown (public, no auth)
- Demo: 5 requests/hour per IP, 50KB body limit, watermarked PDFs
- Landing page: interactive playground replaces 'Get Free API Key'
- Pricing: Demo (free) + Pro (€9/mo), no more Free tier
- /v1/signup returns 410 Gone with redirect to demo/pro
- Keep /v1/recover for existing Pro users
- Update JSON-LD, API discovery, verify page text

src/index.ts

@@ -13,7 +13,7 @@ import rateLimit from "express-rate-limit";
 import { convertRouter } from "./routes/convert.js";
 import { templatesRouter } from "./routes/templates.js";
 import { healthRouter } from "./routes/health.js";
-import { signupRouter } from "./routes/signup.js";
+import { demoRouter } from "./routes/demo.js";
 import { recoverRouter } from "./routes/recover.js";
 import { billingRouter } from "./routes/billing.js";
 import { authMiddleware } from "./middleware/auth.js";
@@ -58,7 +58,8 @@ app.use(compressionMiddleware);
 app.use((req, res, next) => {
   const isAuthBillingRoute = req.path.startsWith('/v1/signup') || 
                              req.path.startsWith('/v1/recover') || 
-                             req.path.startsWith('/v1/billing');
+                             req.path.startsWith('/v1/billing') ||
+                             req.path.startsWith('/v1/demo');
   
   if (isAuthBillingRoute) {
     res.setHeader("Access-Control-Allow-Origin", "https://docfast.dev");
@@ -96,7 +97,14 @@ app.use(limiter);
 
 // Public routes
 app.use("/health", healthRouter);
-app.use("/v1/signup", signupRouter);
+app.use("/v1/demo", express.json({ limit: "50kb" }), pdfRateLimitMiddleware, demoRouter);
+app.use("/v1/signup", (_req, res) => {
+  res.status(410).json({
+    error: "Free accounts have been discontinued. Try our demo at POST /v1/demo/html or upgrade to Pro at https://docfast.dev",
+    demo_endpoint: "/v1/demo/html",
+    pro_url: "https://docfast.dev/#pricing"
+  });
+});
 app.use("/v1/recover", recoverRouter);
 app.use("/v1/billing", billingRouter);
 
@@ -173,7 +181,7 @@ p{color:#7a8194;margin-bottom:24px;line-height:1.6}
 ${apiKey ? `
 <div class="warning">⚠️ Save your API key securely. You can recover it via email if needed.</div>
 <div class="key-box" onclick="navigator.clipboard.writeText('${apiKey}');this.style.borderColor='#5eead4';setTimeout(()=>this.style.borderColor='#34d399',1500)">${apiKey}</div>
-<div class="links">100 free PDFs/month · <a href="/docs">Read the docs →</a></div>
+<div class="links">Upgrade to Pro for 5,000 PDFs/month · <a href="/docs">Read the docs →</a></div>
 ` : `<div class="links"><a href="/">← Back to DocFast</a></div>`}
 </div></body></html>`;
 }
@@ -241,10 +249,11 @@ app.get("/api", (_req, res) => {
     name: "DocFast API",
     version: APP_VERSION,
     endpoints: [
-      "POST /v1/signup/free — Get a free API key",
-      "POST /v1/convert/html",
-      "POST /v1/convert/markdown",
-      "POST /v1/convert/url",
+      "POST /v1/demo/html — Try HTML→PDF (no auth, watermarked, 5/hour)",
+      "POST /v1/demo/markdown — Try Markdown→PDF (no auth, watermarked, 5/hour)",
+      "POST /v1/convert/html — HTML→PDF (requires API key)",
+      "POST /v1/convert/markdown — Markdown→PDF (requires API key)",
+      "POST /v1/convert/url — URL→PDF (requires API key)",
       "POST /v1/templates/:id/render",
       "GET  /v1/templates",
       "POST /v1/billing/checkout — Start Pro subscription",