[P1] Comprehensive Error Handling

[shayonpal]

Description

Implement robust error handling throughout the application with proper logging and user feedback.

Acceptance Criteria

• Create comprehensive exception hierarchy
• Add logging configuration and setup
• Implement retry logic for transient failures
• Include detailed error messages for users
• Handle network connectivity issues
• Add validation for all external inputs
• Ensure no sensitive data in logs or errors

Technical Requirements

• Use Python logging module with appropriate levels
• Create specific exception classes for different error types
• Implement exponential backoff for retries
• Validate all user inputs and file operations
• Handle API rate limits and quotas

Dependencies

• All P0 issues for integration points

Files to Modify

• All existing modules for error handling integration