Add 2 articles on production LLM agents + eval harnesses

[hemangjoshi37a]

Adds two articles to MLOps Articles:

1. The 4 Mistakes That Kill 80% of Enterprise AI Projects — audit framework for stalled LLM/GenAI projects, covering eval harnesses (Ragas), observability, strict output schemas, human-in-the-loop.
2. Deploying Autonomous AI Agents in Production: A 2-Week Playbook — day-by-day deployment guide covering JSON Schema strict mode, Qdrant binary quantization, Cohere Rerank, tiered fallbacks, SLOs.

Both are written from real enterprise engagements (Fortune 500 banks, Gulf SaaS, US healthcare). Content is MIT/CC-BY.

Happy to trim to a single entry or adjust placement if preferred.