Conversation sidebar not navigable with stylus or keyboard - resizer covers scrollbar, list has no focusable container

Environment: Claude desktop app, Windows 11 Pro (10.0.26200), stylus/pen input (no mouse, no scroll wheel)

Description:
Three compounding issues make the conversation list effectively unusable without a scroll wheel:

1. Resizer hit zone covers the scrollbar. The invisible drag zone for the sidebar/chat resizer overlaps the conversation list's scrollbar, leaving ~1px of effective width to grab the thumb. With a pen there is no wheel fallback, so scrolling by scrollbar is effectively impossible.

1. No keyboard scrolling without a destructive click. The list container itself never takes focus - there is no empty/safe area to click that would let arrow keys or Page Up/Down scroll it. Arrow keys do nothing until keyboard focus lands inside the list.

1. The only way to get focus into the list is to activate something. You must click an actual conversation (which navigates away from your current one) or a group title to get focus for arrow-key navigation. "Focus the list" and "open a different conversation" should not be the same gesture.

Expected:

• Scrollbar thumb wins pointer priority over the resizer hit zone (or the resizer zone is inset off the scrollbar track).
• The list is a focusable region (tab stop / clickable track area) with arrow-key and Page Up/Down scrolling that does not require activating an item first.

Steps to reproduce:

1. Open the desktop app with enough conversations for the sidebar to scroll.
2. Try to drag the sidebar scrollbar thumb with a pen/stylus - the resize cursor appears and the panel resizes instead.
3. Press arrow keys / Page Up/Down - nothing scrolls until you click a conversation item, which navigates away.

Impact: Stylus/pen users, wheel-less mice, trackballs, keyboard-only users, and users with limited motor precision.