desktop: move sidebar session archive behind an options menu #20347

In the desktop sidebar, each session row exposes a direct Archive button on the right edge.

That placement makes accidental archives too easy during normal pointer movement and target acquisition, especially because the primary interaction in that area is session navigation.

Expected behavior:

• keep the row focused on navigation
• move session actions behind a compact options menu
• place Archive inside that menu instead of exposing it as a primary inline action

Why this helps:

• reduces accidental destructive clicks
• matches the existing desktop pattern of keeping secondary actions in a more-options menu
• leaves room for additional row actions without crowding the main session list UI