fix(documents-ui): a11y, mobile, realtime lift, type-safety, UI polish

- A2: lift useRealtimeInvalidation to DocumentsHub (covers all 3 render modes)
- B1-B4: aria-label, aria-pressed, aria-expanded, Lock SVG aria-hidden
- C1-C7: Sheet wrap for mobile sidebar, border axis fix, 44x44 tap targets
- Mobile Important: useMobileChrome title, FolderActionsMenu icon size, breadcrumb tap targets, signer email truncate
- Type-safety: ENTITY_TYPES guard, AggregatedSection discriminated union
- UI/UX: em-dash to colon in SigningDetailsDialog, Loading state normalize, StatusPill on HubRootView, view signing details as Button

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/documents/entity-folder-view.tsx

@@ -4,14 +4,15 @@ import { useState } from 'react';
 import Link from 'next/link';
 import { ClipboardSignature, FileText, Eye } from 'lucide-react';
 
+import { Button } from '@/components/ui/button';
 import { AggregatedSection } from './aggregated-section';
 import { SigningDetailsDialog } from './signing-details-dialog';
 import { useAggregatedFiles, useAggregatedWorkflows } from '@/hooks/use-aggregated-listing';
 import { StatusPill, type StatusPillStatus } from '@/components/ui/status-pill';
 import type {
-  AggregatedWorkflow,
   AggregatedFile,
   AggregatedGroup,
+  AggregatedWorkflow,
 } from '@/hooks/use-aggregated-listing';
 
 interface Props {
@@ -47,7 +48,7 @@ export function EntityFolderView({ portSlug, entityType, entityId }: Props) {
 
   return (
     <div className="space-y-4">
-      <AggregatedSection
+      <AggregatedSection<'workflows'>
         title="Signing in progress"
         icon={<ClipboardSignature className="h-4 w-4 text-muted-foreground" />}
         groups={workflowGroups}
@@ -65,7 +66,7 @@ export function EntityFolderView({ portSlug, entityType, entityId }: Props) {
         )}
       />
 
-      <AggregatedSection
+      <AggregatedSection<'files'>
         title="Files"
         icon={<FileText className="h-4 w-4 text-muted-foreground" />}
         groups={fileGroups}
@@ -79,14 +80,15 @@ export function EntityFolderView({ portSlug, entityType, entityId }: Props) {
               <div className="flex items-center gap-2 text-xs text-muted-foreground tabular-nums">
                 <span>{new Date(f.createdAt).toLocaleDateString('en-GB')}</span>
                 {signedFromDocumentId ? (
-                  <button
-                    type="button"
-                    className="flex items-center gap-1 text-brand hover:underline"
+                  <Button
+                    variant="ghost"
+                    size="sm"
+                    className="min-h-[44px] gap-1 px-2 text-xs text-brand"
                     onClick={() => setDetailsId(signedFromDocumentId)}
                   >
                     <Eye className="h-3 w-3" />
-                    view signing details
-                  </button>
+                    View signing details
+                  </Button>
                 ) : null}
               </div>
             </div>