feat(documents): migrate storage to filesystem, add server-side pagination

- Replace Base64 data URIs with file-based storage served via dedicated endpoints
- Add DocumentPreviewModal navigation, DocumentThumbnail fileUrl support
- Refactor documents page with server-side pagination, search, sort and filters
- Update all components to use fileUrl/downloadUrl instead of raw path
- Add pagination composable support (total, page, itemsPerPage, attachmentFilter)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/components/machine/MachineDocumentsCard.vue

@@ -32,8 +32,8 @@
               :class="documentThumbnailClass(doc)"
             >
               <img
-                v-if="isImageDocument(doc) && doc.path"
-                :src="doc.path"
+                v-if="isImageDocument(doc) && (doc.fileUrl || doc.path)"
+                :src="doc.fileUrl || doc.path"
                 class="h-full w-full object-cover"
                 :alt="`Aperçu de ${doc.name}`"
               >