079: Preflight Balance Check Service

[bakarezainab]

#079: Preflight Balance Check Service

Category: [FRONTEND]
Difficulty: ● MEDIUM
Tags: preflight, balance, soroban, stellar, validation

Description

Extend the existing useFeeEstimation hook to run a comprehensive preflight check before any payroll submission: verify the org wallet has sufficient XLM (fees + reserves), has active trustlines for every asset in the batch, and that every employee destination account exists on-chain. Surface per-employee failures clearly in the UI before the user signs.

Acceptance Criteria

• Preflight checks run automatically when the payroll batch is finalised.
• Per-employee rows flagged with the specific failure reason (no account, no trustline, insufficient balance).
• Overall "Ready to Submit" / "Issues Detected" status banner shown.
• User can download a CSV of failed checks.
• Checks re-run after the user resolves an issue without full page reload.