feat: added tool Injection via MCP Elicitation

[yamanahlawat]

Tool Injection via MCP Elicitation

Adds tool injection capability to mcp-run-python, enabling external tools to be dynamically injected into Python execution environments via MCP elicitation protocol.

Changes

• Tool Injection: tool_injection.py module for dynamic tool function injection into Python globals
• MCP Tools: Added discover_available_tools tool and enhanced run_python_code with tool injection
• PydanticAI Extension: mcp_run_python/ext/pydantic_ai.py with create_tool_elicitation_callback() for PydanticAI toolsets

Usage

from mcp_run_python.ext import create_tool_elicitation_callback
callback = create_tool_elicitation_callback(toolset=my_toolset)
# Use callback with MCPServerStdio elicitation_callback parameter

• External tools become available as Python functions during code execution via MCP elicitation protocol

[yamanahlawat]

Should the create_tool_elicitation_callback function be moved to pydantic-ai's extensions instead of keeping it in mcp_run_python/ext/?