feat(web): add multi-format report export (Markdown, HTML, PDF, Word,… (#756)

* feat(web): add multi-format report export (Markdown, HTML, PDF, Word, Image)

* fix: correct import order for docx (lint error)

* fix(web): address Copilot review comments for multi-format export

- Add i18n support for dropdown menu items (en/zh)

- Add DOMPurify for HTML sanitization (XSS protection)

- Fix async handling for canvas.toBlob with Promise wrapper

- Add toast notifications for export errors

- Fix Tooltip + DropdownMenuTrigger nesting (accessibility)

- Ensure container cleanup in finally block

* fix(web): enhance markdown parsing for PDF and Word export

- Add list support (bullet and numbered) for PDF export
- Add parseInlineMarkdown helper for Word export to handle bold, italic, code, links
- Add list support for Word export (bullet and numbered)
- Address Copilot review comments from PR #756

* fix(web): address PR review feedback for multi-format export

- Extract PDF formatting magic numbers into PDF_CONSTANTS

- Add Tooltip wrapper for download dropdown button

- Reduce triggerDownload cleanup timeout from 1000ms to 100ms

- Use marked.Lexer.lexInline for robust markdown parsing

- Add console.warn for image export cleanup errors

- Add numbering config for Word document ordered lists

- Fix CSS class typo: px-5pb-20 -> px-5 pb-20

- Remove unreachable dead code in parseInlineMarkdown

---------

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

web/package.json

@@ -49,21 +49,28 @@
     "@tiptap/extension-table-row": "^2.11.7",
     "@tiptap/extension-text": "^2.12.0",
     "@tiptap/react": "^2.11.7",
+    "@types/dompurify": "^3.2.0",
     "@types/js-cookie": "^3.0.6",
     "@xyflow/react": "^12.6.0",
     "best-effort-json-parser": "^1.1.3",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "cmdk": "^1.1.1",
+    "docx": "^9.5.1",
+    "dompurify": "^3.3.1",
+    "file-saver": "^2.0.5",
     "framer-motion": "^12.6.5",
     "hast": "^1.0.0",
     "highlight.js": "^11.11.1",
+    "html2canvas": "^1.4.1",
     "immer": "^10.1.1",
     "js-cookie": "^3.0.5",
+    "jspdf": "^3.0.4",
     "katex": "^0.16.21",
     "lowlight": "^3.3.0",
     "lru-cache": "^11.1.0",
     "lucide-react": "^0.487.0",
+    "marked": "^17.0.1",
     "motion": "^12.7.4",
     "nanoid": "^5.1.5",
     "next": "^15.4.10",
@@ -94,6 +101,7 @@
     "@tailwindcss/postcss": "^4.0.15",
     "@testing-library/dom": "^10.4.1",
     "@testing-library/react": "^16.3.0",
+    "@types/file-saver": "^2.0.7",
     "@types/hast": "^3.0.4",
     "@types/jest": "^30.0.0",
     "@types/node": "^20.14.10",