Improve error handling and propagation from providers to UI

[rabble]

Problem

Error handling could be more robust throughout the application. Errors from providers and async operations need better propagation to the UI layer for better user experience.

Current Issues

• Provider-level errors often logged but not surfaced
• Inconsistent error handling patterns
• Missing loading and error states in some components
• Network timeouts and failures not gracefully handled

Improvements Needed

• Standardize error handling patterns across providers
• Ensure all async operations have proper error boundaries
• Add consistent loading and error states to UI components
• Implement retry mechanisms for transient failures
• Better error messages for users

Areas to Focus

• Nostr query failures
• Relay connection errors
• Publishing failures
• Authentication errors
• Network timeouts

Acceptance Criteria

• All provider errors properly propagated
• Consistent error UI patterns
• User-friendly error messages
• Graceful degradation for failures
• Error boundaries to prevent crashes