Show only accepted calendar events in the sidebar timeline

[devin-ai-integration]

Summary

Intent: The sidebar timeline listed invitations the user never responded to (e.g. spam "Invitation To Submit Proposal" all-day series). Sync already drops declined events, but pending/tentative ones still showed. The sidebar should only show events the user accepted or organizes.

• useTimelineEventsTable now selects json_extract(attendance_json, '$.self_status') AS self_status (column added in Require calendar attendance before automatic recording #7926).
• deriveTimelineWindowData skips rows with self_status in pending | tentative | declined. They are also excluded from hasMoreFutureItems, and "Show Deleted Events" doesn't bring them back.
• Events with no attendance data, or unknown, organizer, or accepted, are still shown. Personal events with no attendees (gym, etc.) are unaffected.
• This applies to the sidebar timeline and its upcoming-meeting chip, both of which go through deriveTimelineWindowData. The calendar view and tray read the same table but don't use that path, so they don't change.
• Events synced before Require calendar attendance before automatic recording #7926 have attendance_json = NULL and stay visible until the next sync fills it in.

Demo

N/A: this is a filtering change in the sidebar data path and is covered by a unit test. It hasn't been recorded on a calendar with real invites.

Verification

• pnpm -F desktop exec vitest run src/sidebar/timeline src/calendar (new test: deriveTimelineWindowData hides events the user has not accepted)
• pnpm -F desktop typecheck
• pnpm exec dprint fmt, pnpm exec oxlint --quiet on the touched dirs

Link to Devin session: https://app.devin.ai/sessions/117bddedb2ca476ab1f6e116525e6097
Open in Devin Desktop: https://app.devin.ai/desktop/session/117bddedb2ca476ab1f6e116525e6097?variant=devin
Requested by: @ComputelessComputer

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Summary by cubic

Stops the sidebar timeline from listing calendar invitations the user never responded to (pending or tentative invites), so it only shows events the user accepted or organizes.

• Filters out events whose attendance_json self_status is pending, tentative, or declined in deriveTimelineWindowData; they're also excluded from hasMoreFutureItems and not brought back by "Show Deleted Events."
• Events with no attendance data, invalid attendance_json (now treated as missing), or unknown, organizer, or accepted status still show, so personal events without attendees are unaffected.
• Applies to the sidebar timeline and its upcoming-meeting chip; the calendar view and tray read the same table but don't use this path and are unchanged.
• Events synced before attendance_json existed stay visible until the next sync fills the field in; malformed attendance_json is handled the same way and also remains visible.

^{Written for commit fd99c63. Summary will update on new commits.}

[devin-ai-integration]

I'll fix CI failures and address comments from users with write access that start with 'Devin'.

• Disable automatic comment, CI, and merge conflict monitoring

[devin-ai-integration]

✅ Devin resolved the finding on fd99c63

Fixed by Devin (1)

• Malformed attendance empties the event timeline

View all findings in Devin Review