Adding a file expert

[Jake-Pullen]

📝 Pull Request Description

This PR introduces a new File Expert capability to Merlin, allowing the AI assistant to search, read, write, and manage files directly from the user's system. It also includes improvements to configuration handling, version updates, and enhanced response display logic.

🔧 Key Changes

1. New File Expert Module

• Added a new FileAgent in src/experts/file.py that supports:
  • Finding files using the find command
  • Loading file contents
  • Writing or overwriting files
• Integrated into the orchestrator via consult_file_expert() method
• Uses configurable search directories (FILE_SEARCH_DIRECTORIES) defined in both app and user configs

2. Configuration Enhancements

• Updated src/config/app_config.py to include default file search directory (~) and merge with user-defined directories
• Added FILE_SEARCH_DIRECTORIES to src/config/user_config_template.py for easy customization by users
• Refactored imports in app_config.py to avoid duplicate imports

3. Version Updates

• Bumped version from 1.2.4 to 1.3.0 in:
  • pyproject.toml
  • uv.lock (updated litellm dependency from 1.79.0 to 1.79.1)
• Also updated version in src/main.py

4. Orchestrator Integration

• Integrated the new file expert into the main orchestrator (src/experts/orchestrator.py)
• Added documentation for how and when to use this expert

5. UI Improvements

• Updated response display logic in src/main.py:
  • Now shows the routing information as a subtitle in the AI response panel
  • Maintains clean, visually appealing output using Rich's Panel and Markdown

📚 Documentation Update

• Added a new section to README.md titled "File Expert" that describes:
  • How to find, read, and save files
  • User control over where the LLM can look for files

✅ Usage Example

Users can now ask Merlin questions like:

"Find all .md files in my home directory"
"Read the contents of config.yaml"
"Write a new file called notes.txt with the content 'Hello, world!'"

The AI will route these requests to the new File Expert agent, which handles them using system-level file operations.