feat(dataroom): bilingual descriptions, drag-drop multi-file upload, edit existing upload descriptions

- lib/translate.ts: LiteLLM DE<>EN translation utility
- Migration 006: description_de/description_en on both dataroom tables
- Admin + investor upload APIs: accept description+lang, auto-translate the other language on save
- PATCH /api/admin/dataroom/documents/[id]: description path in addition to display_name path
- PATCH /api/dataroom/uploads/[id]: investor can edit their own upload descriptions
- PATCH /api/admin/dataroom/investors/[id]/uploads: admin can edit investor upload descriptions
- All GET queries updated to return description fields
- Admin dataroom: drop zone replaces upload button, multi-file, inline description editor per doc and per investor upload
- Investor dataroom: drop zone, multi-file, description+lang textarea before upload, inline description editing on existing uploads

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

pitch-deck/app/api/dataroom/documents/route.ts

@@ -4,13 +4,14 @@ import { getSessionFromCookie } from '@/lib/auth'
 
 export const dynamic = 'force-dynamic'
 
-export async function GET(request: NextRequest) {
+export async function GET(_request: NextRequest) {
   const session = await getSessionFromCookie()
   if (!session) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
   const investorId = session.sub
 
   const { rows } = await pool.query(
-    `SELECT d.id, d.filename, d.display_name, d.mime_type, d.file_size, r.released_at
+    `SELECT d.id, d.filename, d.display_name, d.description_de, d.description_en,
+            d.mime_type, d.file_size, r.released_at
      FROM dataroom_releases r
      JOIN dataroom_documents d ON d.id = r.document_id
      WHERE r.investor_id = $1