Explain how Smart Wallet handles retries and failed actions

## Description
When using Smart Wallet, some actions may fail or need to be retried due to network issues, user actions, or temporary errors. Right now, it’s not very clear how Smart Wallet behaves in these situations.
Developers may not know whether Smart Wallet automatically retries certain actions, when an action is considered fully failed, or how to safely retry an action themselves. This uncertainty can lead to duplicate actions, confusing UI states, or users clicking the same button multiple times.

## Expected Behavior
The documentation should clearly explain how Smart Wallet handles failed actions and retries. Developers should understand what happens automatically and what they are expected to handle in their own code.

## Proposed Solution
Add a detailed but easy-to-read documentation section that explains common failure scenarios, whether retries happen automatically, and how developers should safely handle retries and user feedback. The explanation should focus on real-world usage and avoid overly technical language.

The issue does not name a documentation file, test, or entry point, so first locate the Smart Wallet documentation and the existing descriptions of failed actions. Done means adding an easy-to-read section covering common failure scenarios, automatic retries, safe developer retries, and user feedback without overly technical language.

Written by the indexing model from the issue text.