feat: add HeroUploadZone component for file uploads and ToolSelectorModal for tool selection

- Implemented HeroUploadZone for drag-and-drop file uploads with support for various file types (PDF, images, video, Word documents).
- Integrated ToolSelectorModal to display available tools based on the uploaded file type.
- Added Zustand store for managing file state across routes.
- Updated multiple tool components to accept files from the new upload zone.
- Enhanced internationalization support with new translations for upload prompts and tool selection.
- Styled the upload zone and modal for improved user experience.

frontend/src/i18n/fr.json

@@ -28,7 +28,18 @@
     "pdfTools": "Outils PDF",
     "imageTools": "Outils d'images",
     "videoTools": "Outils vidéo",
-    "textTools": "Outils de texte"
+    "textTools": "Outils de texte",
+    "uploadCta": "Téléchargez votre fichier",
+    "uploadOr": "ou glissez-déposez votre fichier ici",
+    "uploadSubtitle": "Nous détectons automatiquement le type de fichier et affichons les outils adaptés",
+    "selectTool": "Choisir un outil",
+    "fileDetected": "Nous avons détecté un fichier {{type}}",
+    "unsupportedFile": "Ce type de fichier n'est pas pris en charge. Essayez PDF, Word, images ou vidéo.",
+    "fileTypes": {
+      "image": "Image",
+      "video": "Vidéo",
+      "unknown": "Inconnu"
+    }
   },
   "tools": {
     "pdfToWord": {