Archived tasks leak across accounts after account switch

[charlesvien]

Problem

Archived tasks are not scoped to the account that created them. After switching to a different account, archived tasks from the original (main) account stay visible instead of being filtered out.

Expected behavior

Archived tasks should only be shown for the account that created them. Switching to another account should show only that account's archived tasks, not those from any other account.

Steps to reproduce

1. Sign in to the main account and archive one or more tasks.
2. Switch to another account.
3. Observe that the main account's archived tasks are visible under the new account.