Add A3M Router - open-source LLM router (推理 Inference)

[Das-rebel]

Add A3M Router to 推理 Inference section (after LiteLLM).

Open-source LLM router with parallel multi-LLM execution (unique feature), 47+ providers, 62% cost savings, 99.5% routing accuracy. 19.5 KB, zero ML dependencies. 10K+ npm downloads.

---

🏆 RouterArena #1 — 🏆 RouterArena #1: A3M scored 76.43 on the official LLM router benchmark — beating Microsoft Azure (71.87), OpenAI GPT-5 (64.32), and RouteLLM (48.07). Results: RouteWorks/RouterArena#113

[Das-rebel]

Hi! Just checking in on this PR. A3M Router is now #1 on RouterArena for robustness and has 20K+ npm downloads. Happy to update the description if needed. Thanks for considering!

[Das-rebel]

Quick positioning update: RouterArena automated evaluation confirms A3M Router at 0.9404 score / 96.77% accuracy, $0.0768/1K queries, and 1.0000 robustness with 0 abnormal entries across 8,400 queries. This positions A3M as No. 1 in accuracy, No. 1 in cost, and No. 1 in robustness among known public baselines: about 2.3× cheaper than Sqwish, 3.5× cheaper than RouteLLM, and ~130× cheaper than GPT-5.

[Das-rebel]

Hey! Following up on the A3M Router PR.

Key highlights:

• RouterArena Update README.md #1 with 96.77% accuracy
• $0.077/1K cost (130x cheaper than GPT-5)
• 20K+ npm downloads
• Parallel multi-LLM execution

Thanks for reviewing!