refactor: replace manual fetch effects in PushList with React Query

[coopernetes]

Background

PushList.tsx uses a manual useEffect + fetch pattern for loading push records and status counts. This approach has several drawbacks:

• Triggers react-hooks/set-state-in-effect lint warnings when async state-setting functions are called directly in effect bodies
• Requires Promise.resolve().then() workarounds to satisfy the lint rule
• Does not deduplicate concurrent fetches or handle stale data correctly
• Background refresh intervals are manually managed with setInterval/clearInterval

The load function currently passes the lint check only because the rule was added after that code was written.

Proposed fix

Replace the manual useEffect + fetchPushes / fetchPushCounts calls with React Query (useQuery). This provides:

• Automatic background refetch on a configurable interval
• Deduplication of concurrent requests
• Proper stale-while-revalidate semantics
• No lint workarounds needed

Scope

• PushList.tsx — primary target (load and loadCounts effects)
• Other pages that use manual useEffect + apiFetch may benefit from the same treatment

Notes

• This is a refactor, not a bug fix — the current workaround (Promise.resolve().then()) is acceptable and consistent with the existing codebase
• Tracked here to ensure the lint pattern is addressed properly rather than accumulating more workarounds