Add pip-installable console script

[gyx09212214-prog]

Summary

• rename the package metadata from the generic mcp-server to financial-datasets-mcp-server
• add a financial-datasets-mcp console script that runs the existing stdio MCP server
• document pip install . and the simpler Claude Desktop command configuration

Why

This addresses the packaging gap described in #9. Users can still run the server from a source checkout with uv run server.py, but they can also install it as a local Python package and point MCP clients at a stable command name.

Validation

• python -m py_compile server.py
• parsed pyproject.toml with tomllib
• created a temporary virtual environment and ran pip install .
• verified the installed financial-datasets-mcp console script resolves to server:main