refactor: remove unused json import from server.py

build: add uv.lock for dependency locking

chore: remove hello.py placeholder file

feat: implement Perplexity web search MCP server and test script

chore: add .env.example template for API key configuration

docs: add comprehensive README with installation and usage instructions

build: add mcp, openai, and python-dotenv dependencies

chore: update .gitignore with standard Python patterns

Init uv