fix: pr-bug-scan findings from #1415

[buf0-bot]

Automated fix-PR from pr-bug-scan for parent #1415.

Fixer summary: Awaited kill before refresh in orphan handleKillSession; removed duplicate sessions interval from open-gated effect; hoisted kill-confirm Dialog out of PopoverContent; treated missing snapshot + sessions error as daemonUnreachable.
Typecheck: skipped

Findings addressed

• ✅ [medium] src/renderer/src/components/status-bar/ResourceUsageStatusSegment.tsx — Orphan kill race re-adds the killed row
• ✅ [medium] src/renderer/src/components/status-bar/ResourceUsageStatusSegment.tsx — Duplicate session polling intervals
• ✅ [medium] src/renderer/src/components/status-bar/ResourceUsageStatusSegment.tsx — Kill confirm Dialog mounted inside PopoverContent
• ✅ [low] src/renderer/src/components/status-bar/ResourceUsageStatusSegment.tsx — daemonUnreachable requires snapshot fetch to have failed at least once

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This PR was generated by the pr-bug-scan automation and reviewed by an agent reviewer. Human approval required before merge.

[nwparker]

Closing in favor of #1516.

This PR was branched off the #1415 merge commit and was 62 commits behind main by the time it came up for review. Its raw three-way diff vs current main touched 233 files / -14275 lines, far beyond the 4 ResourceUsageStatusSegment findings the body claims to address.

The most concrete silent-revert this would have caused: commit c28c06a (#1451, "focus the right pane after clicking an agent") reworks navigateToTab in the same file to thread paneKey through SessionRow / WorktreeRow / ResourceTree and call activateTabAndFocusPane(tabId, paneId) instead of setActiveTab(tabId). Merging this PR as-is would have reverted that behaviour back to plain setActiveTab, dropping pane focus on split tabs.

#1516 re-applies only the four fixer findings (orphan kill race, duplicate sessions interval, hoisted kill Dialog, broadened daemonUnreachable) on top of current main, with #1451 preserved. pnpm typecheck:web + pnpm lint pass.