feat: use task summaries endpoint for sidebar loads

[jonathanlab]

See PostHog/posthog#56959

[greptile-apps]

Prompt To Fix All With AI

This is a comment left during a code review.
Path: apps/code/src/renderer/features/sidebar/hooks/useSidebarData.ts
Line: 144-148

Comment:
**`useTasks` polled unconditionally on the optimized path**

When `showAllUsers` is `false`, `useTaskSummaries` is used for sidebar data and `fullTasks` is explicitly discarded (`rawTasks = summaryTasks`). Yet `useTasks` is called without an `enabled` guard, so the heavy `/tasks/` list endpoint is still polled at `TASK_LIST_POLL_INTERVAL_MS` in the background on every sidebar mount — directly undercutting the optimisation this PR introduces. Adding `enabled: showAllUsers` (or an equivalent guard) to the hook options would restrict the full-list poll to only the code path that needs it.

How can I resolve this? If you propose a fix, please make it concise.

_{Reviews (1): Last reviewed commit: "feat: use task summaries endpoint for si..." | Re-trigger Greptile}