feat: production deployment - full update with providers, admin, glossaries, pricing, tests

Major changes across backend, frontend, infrastructure:
- Provider system with model selection (Google, DeepL, OpenAI, Ollama, Google Cloud)
- Admin panel: user management, pricing, settings
- Glossary system with CSV import/export
- Subscription and tier quota management
- Security hardening (rate limiting, API key auth, path traversal fixes)
- Docker compose for dev, prod, and IONOS deployment
- Alembic migrations for new tables
- Frontend: dashboard, pricing page, landing page, i18n (en/fr)
- Test suite and verification scripts

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/app/dashboard/translate/FileDropZone.tsx

@@ -1,8 +1,9 @@
 'use client';
 
 import { useRef } from 'react';
-import { Upload } from 'lucide-react';
+import { Upload, FileSpreadsheet, FileText, Presentation } from 'lucide-react';
 import { cn } from '@/lib/utils';
+import { useI18n } from '@/lib/i18n';
 import type { UseFileUploadReturn } from './types';
 
 interface FileDropZoneProps {
@@ -11,40 +12,72 @@ interface FileDropZoneProps {
 
 export function FileDropZone({ upload }: FileDropZoneProps) {
   const inputRef = useRef<HTMLInputElement>(null);
+  const { t } = useI18n();
 
-  const handleClick = () => {
-    inputRef.current?.click();
-  };
+  const handleClick = () => inputRef.current?.click();
 
   return (
     <div
+      role="button"
+      tabIndex={0}
+      aria-label={t('dashboard.translate.dropzone.uploadAria')}
       className={cn(
-        'relative flex flex-col items-center justify-center gap-3 rounded-lg border-2 border-dashed px-6 py-10 transition-colors cursor-pointer',
+        'relative flex flex-col items-center justify-center gap-6 rounded-2xl border-2 border-dashed',
+        'min-h-[320px] cursor-pointer select-none transition-all duration-200 px-8 py-12',
         upload.isDragOver
-          ? 'border-primary bg-primary/5'
-          : 'border-border bg-muted/30 hover:border-muted-foreground/30'
+          ? 'border-primary bg-primary/8 scale-[1.01]'
+          : 'border-border bg-muted/20 hover:border-primary/50 hover:bg-muted/40'
       )}
       onDragOver={upload.handleDragOver}
       onDragLeave={upload.handleDragLeave}
       onDrop={upload.handleDrop}
       onClick={handleClick}
+      onKeyDown={(e) => e.key === 'Enter' || e.key === ' ' ? handleClick() : undefined}
     >
-      <div className="flex size-12 items-center justify-center rounded-xl bg-secondary">
-        <Upload className="size-5 text-muted-foreground" />
+      {/* Icon */}
+      <div className={cn(
+        'flex size-20 items-center justify-center rounded-2xl transition-colors',
+        upload.isDragOver ? 'bg-primary/15' : 'bg-secondary'
+      )}>
+        <Upload className={cn(
+          'size-9 transition-colors',
+          upload.isDragOver ? 'text-primary' : 'text-muted-foreground'
+        )} />
       </div>
-      <div className="flex flex-col items-center gap-1">
-        <p className="text-sm font-medium text-foreground">
-          Drag & drop your .xlsx, .docx, or .pptx file here
+
+      {/* Text */}
+      <div className="flex flex-col items-center gap-2 text-center">
+        <p className="text-lg font-semibold text-foreground">
+          {t('dashboard.translate.dropzone.title')}
+        </p>
+        <p className="text-sm text-muted-foreground">
+          {t('dashboard.translate.dropzone.subtitle')}
         </p>
-        <p className="text-xs text-muted-foreground">or click to browse</p>
       </div>
+
+      {/* Format badges */}
+      <div className="flex flex-wrap items-center justify-center gap-3">
+        <span className="flex items-center gap-1.5 rounded-lg border border-border/60 bg-background px-3 py-1.5 text-xs font-medium text-muted-foreground">
+          <FileSpreadsheet className="size-3.5 text-green-500" />
+          Excel (.xlsx)
+        </span>
+        <span className="flex items-center gap-1.5 rounded-lg border border-border/60 bg-background px-3 py-1.5 text-xs font-medium text-muted-foreground">
+          <FileText className="size-3.5 text-blue-500" />
+          Word (.docx)
+        </span>
+        <span className="flex items-center gap-1.5 rounded-lg border border-border/60 bg-background px-3 py-1.5 text-xs font-medium text-muted-foreground">
+          <Presentation className="size-3.5 text-orange-500" />
+          PowerPoint (.pptx)
+        </span>
+      </div>
+
       <input
         ref={inputRef}
         type="file"
         accept=".xlsx,.docx,.pptx"
         className="hidden"
         onChange={upload.handleFileSelect}
-        aria-label="Upload file"
+        aria-label={t('dashboard.translate.dropzone.uploadAria')}
       />
     </div>
   );