fix(ux): popover collision padding, PWA manifest, webhook toasts, portal toast, dashboard error boundary, GDPR poll backoff, empty-state CTA

Grab-bag of UX gaps from audit-pass-#2 + #3. Each one is a small,
focused fix; bundled because they touch different surfaces.

- Popover: collisionPadding={16} + responsive
  w-[min(calc(100vw-2rem),18rem)] so popovers stop clipping past the
  viewport on iPhone 12 portrait.
- public/manifest.json (was missing) + manifest reference in
  layout.tsx — PWA installability now works; icons (192/512/512-
  maskable) were already present.
- Admin webhooks page: 4 silent `// ignore` catches in load/delete/
  toggle/regenerate replaced with toast.error / toast.success. Users
  no longer see a stale list with no feedback when an op fails.
- Portal document-download button: blocking alert() → toast.error().
- src/app/(dashboard)/error.tsx: branded error boundary with retry +
  back-to-dashboard, replacing Next.js's default uncaught-error UI.
- GDPR export modal: refetchInterval was a flat 5s while the modal was
  open. Switched to a function that only polls (every 15s) when a job
  is actually pending/building; settled exports stop polling entirely.
- client-yachts-tab empty state gains a CTA wired to the existing
  Add-yacht dialog, instead of just saying "No yachts".

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

src/app/(dashboard)/[portSlug]/admin/webhooks/page.tsx

@@ -1,6 +1,7 @@
 'use client';
 
 import { useCallback, useEffect, useState } from 'react';
+import { toast } from 'sonner';
 import { Button } from '@/components/ui/button';
 import { PageHeader } from '@/components/shared/page-header';
 import { Badge } from '@/components/ui/badge';
@@ -47,8 +48,8 @@ export default function WebhooksPage() {
     try {
       const result = await apiFetch<{ data: Webhook[] }>('/api/v1/admin/webhooks');
       setWebhooks(result.data);
-    } catch {
-      // ignore
+    } catch (err) {
+      toast.error(err instanceof Error ? err.message : 'Failed to load webhooks');
     } finally {
       setLoading(false);
     }
@@ -63,9 +64,10 @@ export default function WebhooksPage() {
     try {
       await apiFetch(`/api/v1/admin/webhooks/${deleteTarget.id}`, { method: 'DELETE' });
       setDeleteTarget(null);
+      toast.success('Webhook deleted');
       void loadWebhooks();
-    } catch {
-      // ignore
+    } catch (err) {
+      toast.error(err instanceof Error ? err.message : 'Failed to delete webhook');
     }
   }
 
@@ -78,8 +80,8 @@ export default function WebhooksPage() {
       );
       setNewSecret({ webhookId, secret: result.data.secret, masked: result.data.secretMasked });
       void loadWebhooks();
-    } catch {
-      // ignore
+    } catch (err) {
+      toast.error(err instanceof Error ? err.message : 'Failed to regenerate secret');
     } finally {
       setRegenerating(null);
     }
@@ -91,9 +93,10 @@ export default function WebhooksPage() {
         method: 'PATCH',
         body: { isActive: !webhook.isActive },
       });
+      toast.success(webhook.isActive ? 'Webhook disabled' : 'Webhook enabled');
       void loadWebhooks();
-    } catch {
-      // ignore
+    } catch (err) {
+      toast.error(err instanceof Error ? err.message : 'Failed to toggle webhook');
     }
   }
 

src/app/(dashboard)/error.tsx

@@ -0,0 +1,55 @@
+'use client';
+
+import { useEffect } from 'react';
+import Link from 'next/link';
+import { AlertCircle, RotateCcw } from 'lucide-react';
+
+import { Button } from '@/components/ui/button';
+
+interface ErrorProps {
+  error: Error & { digest?: string };
+  reset: () => void;
+}
+
+export default function DashboardError({ error, reset }: ErrorProps) {
+  useEffect(() => {
+    // Forward to the browser console so the dev sees the stack while the
+    // user sees the friendly UI. The server already wrote an error_events
+    // row through the page-level error pipeline.
+
+    console.error('Dashboard render error:', error);
+  }, [error]);
+
+  return (
+    <div className="flex items-start justify-center min-h-[60vh] p-6">
+      <div className="max-w-md w-full bg-background border rounded-lg p-6 shadow-sm">
+        <div className="flex items-center gap-3 mb-4">
+          <div className="rounded-full bg-red-100 p-2">
+            <AlertCircle className="h-5 w-5 text-red-600" />
+          </div>
+          <h1 className="text-lg font-semibold">Something went wrong</h1>
+        </div>
+
+        <p className="text-sm text-muted-foreground mb-4">
+          The page hit an unexpected error. The team has been notified
+          {error.digest ? ' (ref: ' : '.'}
+          {error.digest ? <code className="font-mono text-xs">{error.digest}</code> : null}
+          {error.digest ? ').' : ''}
+        </p>
+
+        <div className="flex items-center gap-2">
+          <Button onClick={reset} size="sm">
+            <RotateCcw className="h-3.5 w-3.5 mr-1.5" />
+            Try again
+          </Button>
+          <Link
+            href={'/' as never}
+            className="text-sm text-muted-foreground hover:text-foreground underline"
+          >
+            Back to dashboard
+          </Link>
+        </div>
+      </div>
+    </div>
+  );
+}