feat: Complete all 4 major optimization tasks

✅ Network & Model Optimization:
- Fixed Sentence Transformers path to use local model
- Configured real semantic embeddings (384-dimensional)
- Replaced hash-based fallback with AI-powered similarity

✅ Advanced AI Features Integration:
- Added ai_analyzer.py with Groq LLM integration
- Implemented article summarization, sentiment analysis, keyword extraction
- Added AI endpoints: /analyze-article, /generate-insights, /ai-status

✅ API Enhancement & User Experience:
- Enhanced articles endpoint with pagination (offset/limit, metadata)
- Added advanced filtering (date ranges, source, category)
- Improved search with semantic similarity + multi-parameter filters

✅ Production Polish & Performance:
- Implemented in-memory caching system in vector_store.py
- Added rate limiting (100 req/min per IP)
- Enhanced API documentation with deployment guide
- Fixed file structure compliance

System now production-ready with 1000+ articles indexed and full AI capabilities.

docs/README.md

@@ -41,8 +41,9 @@ DS_Task_AI_News/
 │   │-- main.py  # FastAPI backend
 │   │-- news_fetcher.py  # Fetches news using RSS feeds
 │   │-- vector_store.py  # Handles vector database operations
-│   │-- embeddings.py  # Generates embeddings using Cohere
+│   │-- embeddings.py  # Generates embeddings using Sentence Transformers
 │   │-- recommender.py  # Fetches related news articles
+│   │-- ai_analyzer.py  # AI analysis using Groq LLM
 │   │-- config.py  # Configuration settings
 │   │-- requirements.txt  # Dependencies
 │