feat: add download button to all file views

Adds a dedicated download button (blob-based, works on iOS WebApp)
to file cards, file preview modal, and image lightbox. Previously
only "open in tab" was available which doesn't work for non-browser
file types like .gpx on iOS.

Fixes #462

client/src/components/Files/FileManager.tsx

@@ -1,7 +1,7 @@
 import ReactDOM from 'react-dom'
 import { useState, useCallback, useRef, useEffect } from 'react'
 import { useDropzone } from 'react-dropzone'
-import { Upload, Trash2, ExternalLink, X, FileText, FileImage, File, MapPin, Ticket, StickyNote, Star, RotateCcw, Pencil, Check, ChevronLeft, ChevronRight } from 'lucide-react'
+import { Upload, Trash2, ExternalLink, Download, X, FileText, FileImage, File, MapPin, Ticket, StickyNote, Star, RotateCcw, Pencil, Check, ChevronLeft, ChevronRight } from 'lucide-react'
 import { useToast } from '../shared/Toast'
 import { useTranslation } from '../../i18n'
 import { filesApi } from '../../api/client'
@@ -30,6 +30,18 @@ function formatSize(bytes) {
   return `${(bytes / 1024 / 1024).toFixed(1)} MB`
 }
 
+async function triggerDownload(url: string, filename: string) {
+  const authUrl = await getAuthUrl(url, 'download')
+  const res = await fetch(authUrl)
+  const blob = await res.blob()
+  const a = document.createElement('a')
+  a.href = URL.createObjectURL(blob)
+  a.download = filename
+  document.body.appendChild(a)
+  a.click()
+  setTimeout(() => { URL.revokeObjectURL(a.href); a.remove() }, 100)
+}
+
 function formatDateWithLocale(dateStr, locale) {
   if (!dateStr) return ''
   try {
@@ -113,6 +125,12 @@ function ImageLightbox({ files, initialIndex, onClose }: ImageLightboxProps) {
             title={t('files.openTab')}>
             <ExternalLink size={16} />
           </button>
+          <button
+            onClick={() => triggerDownload(file.url, file.original_name)}
+            style={{ background: 'none', border: 'none', cursor: 'pointer', color: 'rgba(255,255,255,0.7)', display: 'flex', padding: 4 }}
+            title={t('files.download') || 'Download'}>
+            <Download size={16} />
+          </button>
           <button onClick={onClose} style={{ background: 'none', border: 'none', cursor: 'pointer', color: 'rgba(255,255,255,0.7)', display: 'flex', padding: 4 }}>
             <X size={18} />
           </button>
@@ -514,6 +532,10 @@ export default function FileManager({ files = [], onUpload, onDelete, onUpdate,
                 onMouseEnter={e => e.currentTarget.style.color = 'var(--text-primary)'} onMouseLeave={e => e.currentTarget.style.color = 'var(--text-faint)'}>
                 <ExternalLink size={14} />
               </button>
+              <button onClick={() => triggerDownload(file.url, file.original_name)} title={t('files.download') || 'Download'} style={{ padding: 6, background: 'none', border: 'none', cursor: 'pointer', color: 'var(--text-faint)', borderRadius: 6, display: 'flex' }}
+                onMouseEnter={e => e.currentTarget.style.color = 'var(--text-primary)'} onMouseLeave={e => e.currentTarget.style.color = 'var(--text-faint)'}>
+                <Download size={14} />
+              </button>
               {can('file_delete', trip) && <button onClick={() => handleDelete(file.id)} title={t('common.delete')} style={{ padding: 6, background: 'none', border: 'none', cursor: 'pointer', color: 'var(--text-faint)', borderRadius: 6, display: 'flex' }}
                 onMouseEnter={e => e.currentTarget.style.color = '#ef4444'} onMouseLeave={e => e.currentTarget.style.color = 'var(--text-faint)'}>
                 <Trash2 size={14} />
@@ -734,6 +756,13 @@ export default function FileManager({ files = [], onUpload, onDelete, onUpdate,
                   onMouseLeave={e => (e.currentTarget as HTMLElement).style.color = 'var(--text-muted)'}>
                   <ExternalLink size={13} /> {t('files.openTab')}
                 </button>
+                <button
+                  onClick={() => triggerDownload(previewFile.url, previewFile.original_name)}
+                  style={{ display: 'flex', alignItems: 'center', gap: 4, fontSize: 12, color: 'var(--text-muted)', background: 'none', border: 'none', cursor: 'pointer', textDecoration: 'none', padding: '4px 8px', borderRadius: 6, transition: 'color 0.15s' }}
+                  onMouseEnter={e => (e.currentTarget as HTMLElement).style.color = 'var(--text-primary)'}
+                  onMouseLeave={e => (e.currentTarget as HTMLElement).style.color = 'var(--text-muted)'}>
+                  <Download size={13} /> {t('files.download') || 'Download'}
+                </button>
                 <button onClick={() => setPreviewFile(null)}
                   style={{ background: 'none', border: 'none', cursor: 'pointer', color: 'var(--text-faint)', display: 'flex', padding: 4, borderRadius: 6, transition: 'color 0.15s' }}
                   onMouseEnter={e => e.currentTarget.style.color = 'var(--text-primary)'}