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/groups/ToolDetailPanel/ToolDetailPanel.tsx

@@ -115,16 +115,16 @@ export function ToolDetailPanel({
         />
       )}
 
-      <Group>
+      <Group justify="flex-end">
+        {isExecuting && <CancelButton onClick={onCancel}>Cancel</CancelButton>}
         <Button
-          fullWidth
+          size="md"
           onClick={onExecute}
           disabled={isExecuting}
           loading={isExecuting}
         >
           Execute Tool
         </Button>
-        {isExecuting && <CancelButton onClick={onCancel}>Cancel</CancelButton>}
       </Group>
     </Stack>
   );