feat: Robust transaction error-recovery UX

[joelpeace48-cell]

Background & current state

Failed or re-prompt-needed transactions can leave users stuck. errorMapping.js + TransactionStatus.jsx exist, but there's no consistent, actionable recovery UX per error class (rejected, expired, insufficient fee, RPC down, contract revert).

Goal

Provide robust transaction error-recovery UX: each mapped error class offers a clear recovery action (retry, switch wallet, add funds, explorer link).

Technical design

• Extend errorMapping.js to classify errors into actionable categories with recommended recovery actions + copy. TransactionStatus.jsx renders the action(s) (retry, switch wallet, view on explorer, top-up).
• Tie into sponsored tx (NEW-020) for fee issues and circuit-breaker (NEW-037) degraded messaging.

Edge cases

• Unknown error → generic recovery + report option.
• Expired auth entry → re-sign path.
• RPC degraded → "try again shortly" + status.
• User-rejected → friendly re-prompt.

Task breakdown

• Error classification + recovery action map.
• Render actions in TransactionStatus.
• Hooks for retry/switch-wallet/top-up/explorer.
• Tests across error classes.

Acceptance criteria

• Each mapped error class offers a relevant recovery action.

Testing & verification

• Tests simulating each error class → correct action shown.

Out of scope

• Backend error taxonomy (separate).

Dependencies / related

• Builds on errorMapping.js; pairs with NEW-020/037/106.

Difficulty: medium · Effort: M · stellar