Improve Error Handling and User Messages

## Description
The current error handling in the library could be improved to provide more user-friendly error messages and better recovery options.

## Tasks
- [ ] Review all error handling in the codebase
- [ ] Implement more descriptive error messages that suggest solutions
- [ ] Add graceful failure modes for API errors from LLM providers
- [ ] Implement retry mechanisms with exponential backoff for transient failures
- [ ] Create a centralized error handling system
- [ ] Add proper logging with different verbosity levels
- [ ] Document common errors and their solutions

## Expected Result
A more robust library that handles errors gracefully, provides helpful error messages to users, and recovers from transient failures when possible. Users should be able to understand and fix issues quickly based on the error messages.

## Why is this important?
Good error handling improves the user experience and makes the library more robust in production settings, especially when dealing with external APIs that may have transient failures.

## Difficulty
Medium - requires careful review of the codebase and thoughtful error message design