Redesign webapp with minimal style and full backend integration

- New monochrome design system in globals.css (no shadows, tight spacing, system-font)
- Root layout stripped to html/body; home page owns its Header/Footer
- Dashboard fully wired to FastAPI backend: upload, branch, submission, publish, download
- CVTree rebuilt as compact file-tree component driven by real version data
- DiffViewer rebuilt as minimal git-diff display using real patch data
- API client (libs/api.ts) extended with all CRUD operations
- Header redesigned to match minimal style
- Backend: added GET /documents/{id}/versions/{id}/download endpoint for DOCX export

https://claude.ai/code/session_01Xmxm2QLgFBgRJyYD6VukR6

apps/backend/fastapi/app/api/routes/documents.py

@@ -1,11 +1,13 @@
 from __future__ import annotations
 
 from fastapi import APIRouter, Depends, File, Form, HTTPException, UploadFile
+from fastapi.responses import Response
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.api.deps import get_current_user, get_db
 from app.schemas import DocumentListResponse, DocumentResponse
 from app.services.documents import create_document, get_document, list_documents
+from app.services.storage import storage_client
 from dlib.auth import AuthenticatedUser
 
 
@@ -34,6 +36,28 @@ async def get_user_document(
     return DocumentResponse.model_validate(document)
 
 
+@router.get("/{document_id}/versions/{version_id}/download")
+async def download_version_docx(
+    document_id: str,
+    version_id: str,
+    session: AsyncSession = Depends(get_db),
+    user: AuthenticatedUser = Depends(get_current_user),
+):
+    document = await get_document(session, owner_id=user.sub, document_id=document_id)
+    if not document:
+        raise HTTPException(status_code=404, detail="Document not found")
+    version = next((v for v in document.versions if v.id == version_id), None)
+    if not version or not version.artifact_docx_key:
+        raise HTTPException(status_code=404, detail="Version artifact not found")
+    data = storage_client.download_bytes(key=version.artifact_docx_key)
+    slug = f"{document.title.replace(' ', '-')}-{version.branch_name}.docx"
+    return Response(
+        content=data,
+        media_type="application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+        headers={"Content-Disposition": f'attachment; filename="{slug}"'},
+    )
+
+
 @router.post("/", response_model=DocumentResponse)
 async def upload_document(
     title: str = Form(...),