Address PR #1221 review round 4 feedback

- InspectorView: cancel any in-flight stub handshake timer when a new
  connect request arrives or the user disconnects, via a `useRef`-backed
  timer handle. Prevents a stale handshake resolver from overwriting the
  next attempt's connection state.
- InspectorView: document that screens unmount on tab switch (matches
  prior `{activeTab === X && <Screen />}` behavior; local screen state
  resets on every transition). If Phase 3 needs persistence, add
  `keepMounted` to the Transition.
- InspectorView: document the `mih: "100%"` height assumption on
  ScreenStageContainer — depends on `AppShell.Main` providing a definite
  parent height for the stack itself to fill (absolute children render
  regardless, but nested ScrollArea screens may need this).
- ViewHeader: comment the `Select w={140}` magic number — sized to fit
  the longest current tab label ("Resources").

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

clients/web/src/components/groups/ViewHeader/ViewHeader.tsx

@@ -154,6 +154,8 @@ export function ViewHeader(props: ViewHeaderProps) {
             data={props.availableTabs}
             size="sm"
             allowDeselect={false}
+            // Sized to comfortably fit the longest current tab label
+            // ("Resources"). Revisit if longer tabs are added.
             w={140}
           />
         )}