fix(assets-controller): bypass balance cache on every poll tick

[juanmigdr]

Explanation

AccountsApiDataSource polls for balances every 30s, but the underlying ApiPlatformClient caches responses for 60s (STALE_TIMES.BALANCES). Since the poll didn't pass forceUpdate, every other tick was served the cached response instead of hitting the network — balances only actually refreshed every ~60s.

This passes forceUpdate: true on the poll's fetch call so it always bypasses the cache, same as other call sites (unlock, account switch, tx confirmation) already do.

Kept the fix scoped to just the poll instead of removing caching everywhere, since #9591 added forceUpdate specifically to avoid bursts of duplicate calls when multiple triggers fire close together, and the unmerged #9867 ran into that regression by disabling the cache globally.

References

• Related to fix(assets-controller): increase stale and gc time for accounts api request #9591
• Related to (closed) fix: never serve Accounts API balances from cache #9867

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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Note

Low Risk
Narrow cache-bypass on the 30s poll path only; does not change auth or other fetch sites. Slightly more Accounts API traffic on that interval, which is the intended behavior.

Overview
Fixes AccountsApiDataSource polling serving stale balances on roughly every other tick. The 30s poll used fetch() without forceUpdate, so the 60s TanStack balances cache (STALE_TIMES.BALANCES) won.

Recurring pollFn now passes forceUpdate: true so each tick hits the network (staleTime: 0, gcTime: 0), matching other authoritative refreshes. Bypass is scoped to the poll only so nearby unlock/switch/tx triggers still share the cache.

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