fix(web-admin): use html-to-docx browser build and inline images for Word export

Vite was resolving the Node ESM entry which needs Buffer/global; switch to the browser bundle and pre-convert images to data URLs so seals and watermarks embed.

Co-authored-by: Cursor <cursoragent@cursor.com>

web-admin/src/env.d.ts

@@ -17,6 +17,16 @@ declare module 'vue-img-cutter'
 
 declare module 'file-saver'
 
+declare module '@turbodocx/html-to-docx/dist/html-to-docx.browser.esm.js' {
+  const HTMLtoDOCX: (
+    htmlString: string,
+    headerHTMLString?: string | null,
+    documentOptions?: Record<string, unknown>,
+    footerHTMLString?: string | null
+  ) => Promise<Blob | ArrayBuffer>
+  export default HTMLtoDOCX
+}
+
 declare module 'qrcode.vue' {
   export type Level = 'L' | 'M' | 'Q' | 'H'
   export type RenderAs = 'canvas' | 'svg'