feat: surface structured permission details in approval UI

Wire the sidecar's new permissionDetail payload through the frontend:
- Add PermissionDetail interface to sidecar contract
- Add permissionDetail field to PendingApprovalRecord and thread
  through normalization and AryxAppService mapping
- Create PermissionDetailView component with kind-specific rendering:
  shell (command block + warning), write (filename + diff), read (path),
  mcp (server badge + args), url (prominent URL), memory (subject/fact),
  custom-tool (description + args), hook (message + args)
- ApprovalBanner shows structured detail when available, falls back to
  generic text for backward compatibility
- QueuedApprovalsList shows brief kind-specific summaries

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/shared/contracts/sidecar.ts

@@ -181,6 +181,30 @@ export interface AgentActivityEvent {
   toolName?: string;
 }
 
+export interface PermissionDetail {
+  kind: string;
+  intention?: string;
+  command?: string;
+  warning?: string;
+  possiblePaths?: string[];
+  possibleUrls?: string[];
+  hasWriteFileRedirection?: boolean;
+  fileName?: string;
+  diff?: string;
+  newFileContents?: string;
+  path?: string;
+  serverName?: string;
+  toolTitle?: string;
+  args?: Record<string, unknown>;
+  readOnly?: boolean;
+  url?: string;
+  subject?: string;
+  fact?: string;
+  citations?: string;
+  toolDescription?: string;
+  hookMessage?: string;
+}
+
 export interface ApprovalRequestedEvent {
   type: 'approval-requested';
   requestId: string;
@@ -193,6 +217,7 @@ export interface ApprovalRequestedEvent {
   permissionKind?: string;
   title: string;
   detail?: string;
+  permissionDetail?: PermissionDetail;
 }
 
 export interface CommandErrorEvent {