Refactor ServerCard with active server logic, rename StatusIndicator, and polish UI panels

- Rename StatusIndicator to ServerStatusIndicator across all files
- ServerCard: add activeServer/onSetActiveServer props for coordinated
  connection flow — when a card's toggle is switched on, it sets itself
  as the active server, shows "Connecting" status, and dims all other
  cards (opacity + pointerEvents none + inert for full keyboard blocking)
- ServerListScreen: manage activeServer state internally, pass to cards;
  switch to full-width layout with 3-column grid and scrollable card area
- ServerCard: move "Test Client Features" dropdown above ContentViewer
  with min-height row for consistent card heights
- ToolResultPanel: move Clear button to top-right header row
- ToolDetailPanel: right-align Execute Tool button, size md, not full-width
- ListChangedIndicator: bump Refresh button to size sm
- ToolsActive story: expand to 30 tools with titles
- UnconnectedView stories: all servers disconnected, remove Connecting story

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

clients/web/src/components/elements/ConnectionToggle/ConnectionToggle.tsx

@@ -16,7 +16,7 @@ export function ConnectionToggle({
   return (
     <Switch
       size="lg"
-      checked={checked}
+      checked={checked || loading}
       disabled={disabled || loading}
       onChange={(event) => onChange(event.currentTarget.checked)}
     />