fix(confirmations): submit money account deposits without false insufficient funds

[jpuri]

Description

Money Account deposits could not submit: Max was the only amount that cleared the footer, other amounts showed insufficient funds, a $0 pay token left the amount on a skeleton, and switching tokens crashed on a high-precision BigNumber rate.

This aligns deposit encode and Max with mobile (ROUND_DOWN, non-atomic Max), compares the live funding-account balance instead of the money-account snapshot, converts deposit USD with the mUSD rate (not Monad/vault), and shows 0.0 when the selected token has no balance.

Stacked on #45543.

Changelog

CHANGELOG entry: Fixed Money Account deposits failing to submit or showing insufficient funds for amounts other than Max

Related issues

Fixes: https://consensyssoftware.atlassian.net/browse/CONF-1743

Manual testing steps

1. Build and load this branch (yarn start) with the Money Account feature flag enabled and a wallet that has a Money Account plus a small funding balance (for example ETH or a stablecoin).
2. Start Add funds from the Money Account.
3. Confirm Pay with is a token that has a balance, not destination mUSD at $0.00.
4. Tap Max and confirm the footer allows Add funds.
5. Tap 10%, 25%, and 50%, and type an amount below the Pay-with balance. Confirm the footer still allows Add funds.
6. Type an amount above the Pay-with balance. Confirm the footer blocks with insufficient funds.
7. Open Pay with, select a different token, and confirm the confirmation does not crash.
8. If Pay with is a $0 token, confirm the amount shows 0.0 instead of a skeleton.
9. Submit a Max deposit and a non-Max deposit and confirm both complete.

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Extension Coding Standards.
• I've completed the PR template to the best of my ability
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[github-actions]

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[metamask-ci]

✨ Files requiring CODEOWNER review ✨

✅ @MetaMask/confirmations (27 files, +1958 -156)

• 📁 app/
  • 📁 scripts/
    • 📁 lib/
      • 📁 transaction/
        • 📄 delegation.test.ts +292 -0
        • 📄 delegation.ts +277 -5
• 📁 ui/
  • 📁 pages/
    • 📁 confirmations/
      • 📁 components/
        • 📁 rows/
          • 📁 pay-with-row/
            • 📄 pay-with-row.test.tsx +40 -16
            • 📄 pay-with-row.tsx +5 -5
      • 📁 hooks/
        • 📁 alerts/
          • 📁 transactions/
            • 📄 useAccountNoFundsAlert.test.tsx +22 -0
            • 📄 useAccountNoFundsAlert.ts +6 -1
            • 📄 useInsufficientBalanceAlerts.test.ts +15 -0
            • 📄 useInsufficientBalanceAlerts.ts +13 -2
            • 📄 useInsufficientPayTokenBalanceAlert.test.ts +166 -7
            • 📄 useInsufficientPayTokenBalanceAlert.ts +96 -5
        • 📁 pay/
          • 📄 useAutomaticTransactionPayToken.test.tsx +46 -15
          • 📄 useAutomaticTransactionPayToken.ts +33 -13
          • 📄 useIsPaidByMetaMask.test.ts +47 -3
          • 📄 useIsPaidByMetaMask.ts +22 -5
          • 📄 usePayTokenAccountBalance.test.ts +242 -0
          • 📄 usePayTokenAccountBalance.ts +122 -0
          • 📄 usePayWithNoFeeToken.test.tsx +23 -0
          • 📄 usePayWithNoFeeToken.tsx +21 -5
          • 📄 usePayWithToken.test.tsx +28 -0
          • 📄 usePayWithToken.tsx +9 -0
          • 📄 useTransactionPayAvailableTokens.test.tsx +8 -0
          • 📄 useTransactionPayAvailableTokens.ts +4 -1
        • 📁 transactions/
          • 📄 useDepositPrefillAmount.test.ts +34 -6
          • 📄 useDepositPrefillAmount.ts +16 -8
          • 📄 useTransactionCustomAmount.test.ts +269 -4
          • 📄 useTransactionCustomAmount.ts +99 -53
      • 📁 selectors/
        • 📄 feature-flags.ts +3 -2