…MetaMask#30414)

## **Description**

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After switching the selected EVM account, the Spending Limit screen's
**Token** selector rendered the "No tokens available" empty state, even
when the new account had supported tokens that could be enabled. The
root cause was introduced in MetaMask#30028:
`BaanxProvider.buildSupportedTokens` synthesized the "Not enabled"
placeholder rows once at fetch time and stamped them with the account
that was selected during the fetch. `cardHomeData` is not refetched on a
plain account switch, so the stale `walletAddress` on those placeholders
no longer matched the new selected account and the downstream filter in
`selectCardAvailableTokens` removed them all.

Rather than triggering a network refetch on every account change (the
`getCardHomeData` call is heavy), this PR moves the placeholder
synthesis into the selector layer so the list is recomputed reactively
from data that is already in the store.

- `BaanxProvider.buildSupportedTokens` no longer creates inactive
placeholders or takes a `currentWalletAddress`. Its sole responsibility
is now to enrich the real `fundingAssets` with the matching
`delegationContract` from `delegationSettings`.
- `selectCardAvailableTokens` now combines `cardHomeData`, the selected
EVM account, and `selectCardFeatureFlag`. It returns the filtered real
entries **plus** Inactive placeholders synthesized from
`delegationSettings` via `buildDelegationTokenList`, each stamped with
the currently selected wallet address. Memoization keeps recomputation
cheap.
- `selectCardLineaUsdcToken` is rebased on `selectCardAvailableTokens`
so the Cashback screen also benefits from the synthesized USDC-on-Linea
placeholder.

No data-fetching or controller subscription is added; the selector
recomputes from already-cached state.

## **Changelog**

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CHANGELOG entry: Fixed a bug where the Card spending-limit token
selector incorrectly showed "No tokens available" after switching
accounts.

## **Related issues**

Refs: MetaMask#30028

## **Manual testing steps**

```gherkin
Feature: Card spending-limit token selector reflects the selected account

  Scenario: Token list reflects the new account after switching
    Given the Card feature is enabled
      And I have at least two EVM accounts (Account A and Account B)
      And Account A has at least one Card-supported token enabled (e.g. USDC on Linea)
      And Account B has no Card token enabled yet
      And the Card spending-limit screen is open with Account A selected
      And the Token selector shows the supported tokens

    When I switch the selected account to Account B
      And I open the Token selector

    Then the Token selector lists the Card-supported tokens (e.g. USDC on Linea) as "Not enabled" for Account B
      And it does NOT show the "No tokens available" empty state
      And no Card home-data network refetch is triggered by the account switch

  Scenario: Real funding assets keep being shown alongside placeholders
    Given I have an account with at least one delegated Card token (Active)

    When I open the Card spending-limit screen for that account

    Then the Active token is shown with its enabled state
      And any other Card-supported tokens that are not yet enabled appear as "Not enabled" placeholders
      And the placeholders are stamped with the currently selected wallet address

  Scenario: Cashback Linea USDC continues to work
    Given the Card feature is enabled
      And the selected account has not yet enabled USDC on Linea

    When I open the Cashback flow

    Then USDC on Linea is detected as the cashback token (via the synthesized placeholder)
      And the "Linea funding requirement" path renders as expected
```

## **Screenshots/Recordings**

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before and after of your change. -->

### **Before**

N/A

### **After**

N/A

## **Pre-merge author checklist**

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"Ready for review". A checked box means you deliberately considered that
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- [x] I've followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask Mobile
Coding
Standards](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/CODING_GUIDELINES.md).
- [x] I've completed the PR template to the best of my ability
- [x] I've included tests if applicable
- [x] I've documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [x] I've applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

#### Performance checks (if applicable)

- [ ] I've tested on Android
  - Ideally on a mid-range device; emulator is acceptable
- [ ] I've tested with a power user scenario
- Use these [power-user
SRPs](https://consensyssoftware.atlassian.net/wiki/spaces/TL1/pages/edit-v2/401401446401?draftShareId=9d77e1e1-4bdc-4be1-9ebb-ccd916988d93)
to import wallets with many accounts and tokens
- [ ] I've instrumented key operations with Sentry traces for production
performance metrics
- See [`trace()`](/app/util/trace.ts) for usage and
[`addToken`](/app/components/Views/AddAsset/components/AddCustomToken/AddCustomToken.tsx#L274)
for an example

For performance guidelines and tooling, see the [Performance
Guide](https://consensyssoftware.atlassian.net/wiki/spaces/TL1/pages/400085549067/Performance+Guide+for+Engineers).

## **Pre-merge reviewer checklist**

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checklist: an
unchecked box is ambiguous, a checked box means the reviewer consciously
assessed that responsibility. See `docs/readme/ready-for-review.md`.
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- [ ] 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.

<!-- Generated with the help of the pr-description AI skill -->

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Medium Risk**
> Moves token placeholder synthesis from provider fetch-time to selector
projection-time, changing what tokens are shown and how they’re sorted
after account switches. Risk is moderate because it affects
spending-limit and cashback token selection logic across wallets but is
covered by updated tests.
> 
> **Overview**
> Fixes an account-switch bug where the spending-limit token picker
could show *no tokens available* by **moving “Not enabled” placeholder
creation out of `BaanxProvider.buildSupportedTokens` and into
`selectCardAvailableTokens`**, so placeholders are stamped with the
*currently selected* EVM wallet without refetching home data.
> 
> `BaanxProvider.buildSupportedTokens` now only enriches real
`fundingAssets` with `delegationContract`, while selectors synthesize
delegation-derived placeholders via `buildDelegationTokenList`, dedupe
against real entries for the current wallet, and apply a deterministic
sort (priority then status). `selectCardLineaUsdcToken` is updated to
fall back to the delegation-derived placeholder (for Cashback/Linea
USDC), and tests are updated/expanded to validate placeholder behavior,
account switching, and ordering.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
336c0bd. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->