Changes

• Add local file cache for financial API responses (prices, crypto, SEC filings) to eliminate redundant network calls for historical data
• Add Anthropic prompt caching via cache_control for ~90% input token cost savings on repeated calls
• Add performance metrics display showing token usage, duration, and tokens/second after each query
• Add GitHub Actions CI workflow running typecheck and tests on push/PR

Fixes

• Fix Exa search client version incompatibility between exa-js 2.x and @langchain/exa