feat(dashboard): add pre-copy confirmation modal showing what will and won't be copied

Introduces CopyTripDialog — a two-section modal that appears before the
copy action and lists what is carried over (days, places, budget items,
packing lists, TODOs, notes) and what is intentionally skipped
(collaborators, collab data, files, share tokens). Addresses the UX gap
raised in #786.

client/src/components/shared/CopyTripDialog.tsx

@@ -0,0 +1,108 @@
+import React, { useEffect, useCallback } from 'react'
+import { Check, X } from 'lucide-react'
+import { useTranslation } from '../../i18n'
+
+interface CopyTripDialogProps {
+  isOpen: boolean
+  tripTitle: string
+  onClose: () => void
+  onConfirm: () => void
+}
+
+const WILL_COPY_KEYS = [
+  'dashboard.confirm.copy.will1',
+  'dashboard.confirm.copy.will2',
+  'dashboard.confirm.copy.will3',
+  'dashboard.confirm.copy.will4',
+  'dashboard.confirm.copy.will5',
+  'dashboard.confirm.copy.will6',
+]
+
+const WONT_COPY_KEYS = [
+  'dashboard.confirm.copy.wont1',
+  'dashboard.confirm.copy.wont2',
+  'dashboard.confirm.copy.wont3',
+  'dashboard.confirm.copy.wont4',
+]
+
+export default function CopyTripDialog({ isOpen, tripTitle, onClose, onConfirm }: CopyTripDialogProps) {
+  const { t } = useTranslation()
+
+  const handleEsc = useCallback((e: KeyboardEvent) => {
+    if (e.key === 'Escape') onClose()
+  }, [onClose])
+
+  useEffect(() => {
+    if (isOpen) document.addEventListener('keydown', handleEsc)
+    return () => document.removeEventListener('keydown', handleEsc)
+  }, [isOpen, handleEsc])
+
+  if (!isOpen) return null
+
+  return (
+    <div
+      className="fixed inset-0 z-[10000] flex items-center justify-center px-4 trek-backdrop-enter"
+      style={{ backgroundColor: 'rgba(15, 23, 42, 0.5)' }}
+      onClick={onClose}
+    >
+      <div
+        className="trek-modal-enter rounded-2xl shadow-2xl w-full max-w-md p-6"
+        style={{ background: 'var(--bg-card)' }}
+        onClick={e => e.stopPropagation()}
+      >
+        <h3 className="text-base font-semibold mb-1" style={{ color: 'var(--text-primary)' }}>
+          {t('dashboard.confirm.copy.title')}
+        </h3>
+        <p className="text-sm mb-4" style={{ color: 'var(--text-secondary)' }}>
+          {tripTitle}
+        </p>
+
+        <div className="flex flex-col gap-3">
+          <div className="rounded-xl p-3" style={{ background: 'var(--bg-subtle)', border: '1px solid var(--border-secondary)' }}>
+            <p className="text-xs font-semibold uppercase tracking-wide mb-2" style={{ color: '#16a34a' }}>
+              {t('dashboard.confirm.copy.willCopy')}
+            </p>
+            <ul className="flex flex-col gap-1">
+              {WILL_COPY_KEYS.map(key => (
+                <li key={key} className="flex items-center gap-2 text-sm" style={{ color: 'var(--text-secondary)' }}>
+                  <Check size={13} className="flex-shrink-0" style={{ color: '#16a34a' }} />
+                  {t(key)}
+                </li>
+              ))}
+            </ul>
+          </div>
+
+          <div className="rounded-xl p-3" style={{ background: 'var(--bg-subtle)', border: '1px solid var(--border-secondary)' }}>
+            <p className="text-xs font-semibold uppercase tracking-wide mb-2" style={{ color: 'var(--text-muted)' }}>
+              {t('dashboard.confirm.copy.wontCopy')}
+            </p>
+            <ul className="flex flex-col gap-1">
+              {WONT_COPY_KEYS.map(key => (
+                <li key={key} className="flex items-center gap-2 text-sm" style={{ color: 'var(--text-secondary)' }}>
+                  <X size={13} className="flex-shrink-0" style={{ color: 'var(--text-muted)' }} />
+                  {t(key)}
+                </li>
+              ))}
+            </ul>
+          </div>
+        </div>
+
+        <div className="flex justify-end gap-3 mt-5">
+          <button
+            onClick={onClose}
+            className="px-4 py-2 text-sm font-medium rounded-lg transition-colors"
+            style={{ color: 'var(--text-secondary)', border: '1px solid var(--border-secondary)' }}
+          >
+            {t('common.cancel')}
+          </button>
+          <button
+            onClick={() => { onConfirm(); onClose() }}
+            className="px-4 py-2 text-sm font-medium rounded-lg transition-colors text-white bg-blue-600 hover:bg-blue-700"
+          >
+            {t('dashboard.confirm.copy.confirm')}
+          </button>
+        </div>
+      </div>
+    </div>
+  )
+}

client/src/i18n/translations/en.ts

@@ -122,6 +122,20 @@ const en: Record<string, string | { name: string; category: string }[]> = {
   'dashboard.toast.copied': 'Trip copied!',
   'dashboard.toast.copyError': 'Failed to copy trip',
   'dashboard.confirm.delete': 'Delete trip "{title}"? All places and plans will be permanently deleted.',
+  'dashboard.confirm.copy.title': 'Copy this trip?',
+  'dashboard.confirm.copy.willCopy': 'Will be copied',
+  'dashboard.confirm.copy.will1': 'Days, places & day assignments',
+  'dashboard.confirm.copy.will2': 'Accommodations & reservations',
+  'dashboard.confirm.copy.will3': 'Budget items & category order',
+  'dashboard.confirm.copy.will4': 'Packing lists (unchecked)',
+  'dashboard.confirm.copy.will5': 'TODOs (unassigned & unchecked)',
+  'dashboard.confirm.copy.will6': 'Day notes',
+  'dashboard.confirm.copy.wontCopy': "Won't be copied",
+  'dashboard.confirm.copy.wont1': 'Collaborators & member assignments',
+  'dashboard.confirm.copy.wont2': 'Collab notes, polls & messages',
+  'dashboard.confirm.copy.wont3': 'Files & photos',
+  'dashboard.confirm.copy.wont4': 'Share tokens',
+  'dashboard.confirm.copy.confirm': 'Copy trip',
   'dashboard.editTrip': 'Edit Trip',
   'dashboard.createTrip': 'Create New Trip',
   'dashboard.tripTitle': 'Title',

client/src/pages/DashboardPage.test.tsx

@@ -401,6 +401,10 @@ describe('DashboardPage', () => {
       const copyButtons = screen.getAllByRole('button', { name: /copy/i });
       await user.click(copyButtons[0]);
 
+      // Confirm the copy dialog
+      const confirmButton = await screen.findByRole('button', { name: /copy trip/i });
+      await user.click(confirmButton);
+
       await waitFor(() => {
         expect(screen.getAllByText('Paris Adventure (Copy)')[0]).toBeInTheDocument();
       });
@@ -766,6 +770,10 @@ describe('DashboardPage', () => {
       expect(copyButtons.length).toBeGreaterThan(0);
       await user.click(copyButtons[0]);
 
+      // Confirm the copy dialog
+      const confirmButton = await screen.findByRole('button', { name: /copy trip/i });
+      await user.click(confirmButton);
+
       await waitFor(() => {
         expect(screen.getAllByText('Paris Adventure (Copy)').length).toBeGreaterThan(0);
       });

client/src/pages/DashboardPage.tsx

@@ -12,6 +12,7 @@ import CurrencyWidget from '../components/Dashboard/CurrencyWidget'
 import TimezoneWidget from '../components/Dashboard/TimezoneWidget'
 import TripFormModal from '../components/Trips/TripFormModal'
 import ConfirmDialog from '../components/shared/ConfirmDialog'
+import CopyTripDialog from '../components/shared/CopyTripDialog'
 import { useToast } from '../components/shared/Toast'
 import { useCountUp } from '../hooks/useCountUp'
 import {
@@ -699,6 +700,7 @@ export default function DashboardPage(): React.ReactElement {
   const [showWidgetSettings, setShowWidgetSettings] = useState<boolean | 'mobile' | 'mobile-currency' | 'mobile-timezone'>(false)
   const [viewMode, setViewMode] = useState<'grid' | 'list'>(() => (localStorage.getItem('trek_dashboard_view') as 'grid' | 'list') || 'grid')
   const [deleteTrip, setDeleteTrip] = useState<DashboardTrip | null>(null)
+  const [copyTrip, setCopyTrip] = useState<DashboardTrip | null>(null)
 
   const toggleViewMode = () => {
     setViewMode(prev => {
@@ -815,14 +817,18 @@ export default function DashboardPage(): React.ReactElement {
     setArchivedTrips(prev => prev.map(update))
   }
 
-  const handleCopy = async (trip: DashboardTrip) => {
+  const handleCopy = (trip: DashboardTrip) => setCopyTrip(trip)
+
+  const confirmCopy = async () => {
+    if (!copyTrip) return
     try {
-      const data = await tripsApi.copy(trip.id, { title: `${trip.title} (${t('dashboard.copySuffix')})` })
+      const data = await tripsApi.copy(copyTrip.id, { title: `${copyTrip.title} (${t('dashboard.copySuffix')})` })
       setTrips(prev => sortTrips([data.trip, ...prev]))
       toast.success(t('dashboard.toast.copied'))
     } catch {
       toast.error(t('dashboard.toast.copyError'))
     }
+    setCopyTrip(null)
   }
 
   const today = new Date().toISOString().split('T')[0]
@@ -1205,6 +1211,13 @@ export default function DashboardPage(): React.ReactElement {
         message={t('dashboard.confirm.delete', { title: deleteTrip?.title || '' })}
       />
 
+      <CopyTripDialog
+        isOpen={!!copyTrip}
+        tripTitle={copyTrip?.title || ''}
+        onClose={() => setCopyTrip(null)}
+        onConfirm={confirmCopy}
+      />
+
       <style>{`
         @keyframes pulse {
           0%, 100% { opacity: 1 }