fix(desktop): make the host connection strip clickable over the tab bar drag region
Problem
The host connection strip ("Connecting… / Details / Retry") sits over the pane tab bar. The bar's empty filler is an Electron window-drag region, and Chromium computes drag regions from element rectangles regardless of stacking order, so clicks on the pill became window drags and the buttons never fired.
Fix
Add no-drag to the pill. Same carve-out pattern the tab bar already uses for its own controls.
Verification
Class-only change, lint clean. Not exercised in the app: the strip only shows while a host is unreachable.
Summary by cubic
Fixes the host connection strip so its Details and Retry buttons receive clicks instead of being swallowed by the tab bar's window-drag region.
The strip sits over the tab bar, whose empty filler is an Electron drag region. Chromium builds drag regions from element rectangles regardless of stacking order, so clicks on the pill became window drags. Adding no-drag to the pill restores button clicks, matching the carve-out the tab bar already uses for its own controls.