Address PR #1221 code review feedback

- Fix getCapabilityEntries to iterate fixed key sets so unsupported
  capabilities render red X (was only showing present/supported ones)
- Merge duplicate @mantine/core import in ViewHeader
- Move ConnectionState from ServerCard to core/mcp/types.ts
- Narrow onConnectionModeChange to "proxy" | "direct" instead of string

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

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

@@ -22,7 +22,7 @@ export interface ServerSettingsFormProps {
   settings: InspectorServerSettings;
   expandedSections: ServerSettingsSection[];
   onExpandedSectionsChange: (sections: ServerSettingsSection[]) => void;
-  onConnectionModeChange: (mode: string) => void;
+  onConnectionModeChange: (mode: "proxy" | "direct") => void;
   onAddHeader: () => void;
   onRemoveHeader: (index: number) => void;
   onHeaderChange: (index: number, key: string, value: string) => void;
@@ -129,7 +129,7 @@ export function ServerSettingsForm({
             data={CONNECTION_MODE_OPTIONS}
             value={settings.connectionMode}
             onChange={(value) => {
-              if (value) onConnectionModeChange(value);
+              if (value) onConnectionModeChange(value as "proxy" | "direct");
             }}
             description={
               settings.connectionMode === "proxy"