Add Stellar account monitoring utilities

[meshackyaro]

Description

No utilities for monitoring platform account balance. Risk of operations failing due to insufficient XLM.

Component

SDK

Difficulty

🟡 Medium

Tasks

• Add account balance monitoring
• Implement low balance warnings
• Add balance threshold configuration
• Provide webhook notifications
• Document monitoring setup

Acceptance Criteria

• Account balance tracked automatically
• Alerts triggered below threshold
• Monitoring configurable

Estimated Time

2 days