feat: enable 'always approve for session' for runtime tools

Runtime tool permission requests (read, write, shell, store_memory) now
resolve stable approval names via fallback in the sidecar approval
coordinator, enabling the 'Always approve' button and session-level
auto-approval for built-in tools.

Backend:
- Add fallback tool names for PermissionRequestRead (read),
  PermissionRequestWrite (write), PermissionRequestShell (shell),
  and PermissionRequestMemory (store_memory)
- Add autoApprovedToolName parameter to RequiresToolCallApproval
  for permission-kind-based session approval matching
- Track tool.execution_start events in ToolNamesByCallId for
  supplementary exact-name resolution

Frontend:
- Use approval.toolName ?? approval.permissionKind as fallback key
  in resolveSessionApproval and ApprovalBanner
- Add shell, read, write permission-kind entries to builtin approval
  tool definitions so pruning preserves session overrides

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

src/renderer/components/chat/ApprovalBanner.tsx

@@ -23,7 +23,8 @@ export function ApprovalBanner({
   const kindLabel = approval.kind === 'final-response' ? 'Final response review' : 'Tool call approval';
   const hasMessages = approval.messages && approval.messages.length > 0;
   const showPosition = position !== undefined && total !== undefined && total > 1;
-  const canAlwaysApprove = approval.kind === 'tool-call' && !!approval.toolName;
+  const approvalToolKey = approval.toolName ?? approval.permissionKind;
+  const canAlwaysApprove = approval.kind === 'tool-call' && !!approvalToolKey;
 
   return (
     <div className="rounded-xl border border-amber-500/30 bg-amber-500/5 px-4 py-3" role="alert">
@@ -90,11 +91,11 @@ export function ApprovalBanner({
         </button>
         {canAlwaysApprove && (
           <button
-            aria-label={`Always approve ${approval.toolName}`}
+            aria-label={`Always approve ${approvalToolKey}`}
             className="inline-flex items-center gap-1.5 rounded-lg bg-emerald-600/20 px-3.5 py-1.5 text-[12px] font-medium text-emerald-300 transition hover:bg-emerald-600/30 disabled:cursor-not-allowed disabled:opacity-50"
             disabled={isResolving}
             onClick={() => onResolve('approved', true)}
-            title={`Auto-approve "${approval.toolName}" for the rest of this session`}
+            title={`Auto-approve "${approvalToolKey}" for the rest of this session`}
             type="button"
           >
             <ShieldBan className="size-3" />