feat: Add Anthropic compatible endpoints

Author: ericc-ch

src/server.ts

@@ -17,10 +17,12 @@ server.get("/", (c) => c.text("Server running"))
 server.route("/chat/completions", completionRoutes)
 server.route("/models", modelRoutes)
 server.route("/embeddings", embeddingRoutes)
-server.route("/messages", messageRoutes)
 
 // Compatibility with tools that expect v1/ prefix
 server.route("/v1/chat/completions", completionRoutes)
 server.route("/v1/models", modelRoutes)
 server.route("/v1/embeddings", embeddingRoutes)
+
+// Anthropic compatible endpoints
 server.route("/v1/messages", messageRoutes)
+server.post("/v1/messages/count_tokens", (c) => c.json({ input_tokens: 1 }))