refactor : merge Inventory_frontend submodule into frontend/ directory

Merges the full git history of Inventory_frontend into the monorepo
under frontend/. Removes the submodule in favor of a unified repo.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/app/shared/utils/documentDisplayUtils.ts

@@ -0,0 +1,77 @@
+/**
+ * Document display & preview helpers for edit pages.
+ *
+ * Extracted from pages/component/[id]/edit.vue, pieces/[id]/edit.vue,
+ * product/[id]/edit.vue – each had an identical copy of these utilities.
+ */
+
+import { getFileIcon } from '~/utils/fileIcons'
+import { isImageDocument, isPdfDocument } from '~/utils/documentPreview'
+
+export const PDF_PREVIEW_MAX_BYTES = 5 * 1024 * 1024
+
+export const formatSize = (size: number | null | undefined): string => {
+  if (size === null || size === undefined) return '—'
+  if (size === 0) return '0 B'
+  const units = ['B', 'KB', 'MB', 'GB']
+  const index = Math.min(units.length - 1, Math.floor(Math.log(size) / Math.log(1024)))
+  const formatted = size / Math.pow(1024, index)
+  return `${formatted.toFixed(1)} ${units[index]}`
+}
+
+const resolveUrl = (doc: any): string => doc?.fileUrl || doc?.path || ''
+
+export const shouldInlinePdf = (doc: any): boolean => {
+  if (!doc || !isPdfDocument(doc)) return false
+  const url = resolveUrl(doc)
+  if (!url) return false
+  if (typeof doc.size === 'number' && doc.size > PDF_PREVIEW_MAX_BYTES) return false
+  return true
+}
+
+export const appendPdfViewerParams = (src: string): string => {
+  if (!src) return ''
+  if (src.startsWith('data:')) return src
+  if (src.includes('#')) return `${src}&toolbar=0&navpanes=0`
+  return `${src}#toolbar=0&navpanes=0`
+}
+
+export const documentPreviewSrc = (doc: any): string => {
+  const url = resolveUrl(doc)
+  if (!url) return ''
+  if (isPdfDocument(doc)) return appendPdfViewerParams(url)
+  return url
+}
+
+export const documentThumbnailClass = (doc: any): string => {
+  if (shouldInlinePdf(doc) || (isImageDocument(doc) && resolveUrl(doc))) return 'h-24 w-20'
+  return 'h-16 w-16'
+}
+
+export interface FileIconResult {
+  component: unknown
+  colorClass: string
+  label: string
+}
+
+export const documentIcon = (doc: any): FileIconResult =>
+  getFileIcon({ name: doc?.filename || doc?.name, mime: doc?.mimeType })
+
+export const downloadDocument = (doc: any): void => {
+  // Prefer dedicated download endpoint
+  if (doc?.downloadUrl) {
+    window.open(doc.downloadUrl, '_blank')
+    return
+  }
+  // Fallback for legacy data: URIs during migration
+  const target = resolveUrl(doc)
+  if (!target) return
+  if (target.startsWith('data:')) {
+    const link = document.createElement('a')
+    link.href = target
+    link.download = doc.filename || doc.name || 'document'
+    link.click()
+    return
+  }
+  window.open(target, '_blank')
+}