feat(frontend): convertit l'ensemble des pages et composants au DSFR

- composants UI (Input, Card, Badge, Modal, ConfirmDialog, Slider, Skeleton,
  ThemeToggle) + Sidebar
- pages auth (connexion, inscription)
- pages publiques (informations, détail, contacts urgence, mentions, RGPD)
- espace membre (dashboard, journal, wizard saisie via fr-stepper, rapports, profil)
  + composants tracker (EditSaisieModal, EmotionPicker, TrackerTimeline, EmotionChart)
- back-office admin (dashboard, utilisateurs, contenus, émotions)

Suppression de Tailwind candlelight/malachite + lucide-react. Build OK (20 routes).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/components/ui/ConfirmDialog.tsx

@@ -1,6 +1,5 @@
 "use client";
 
-import { AlertTriangle } from "lucide-react";
 import Modal from "./Modal";
 import Button from "./Button";
 
@@ -27,42 +26,26 @@ export default function ConfirmDialog({
 }: ConfirmDialogProps) {
   return (
     <Modal isOpen={isOpen} onClose={onClose} title={title} size="sm">
-      <div className="flex items-start gap-3 mb-6">
-        <div
-          className={`flex-shrink-0 w-10 h-10 rounded-full flex items-center justify-center ${
-            destructive
-              ? "bg-red-50 dark:bg-red-950/40"
-              : "bg-malachite-50 dark:bg-malachite-950/40"
-          }`}
-        >
-          <AlertTriangle
-            size={20}
-            className={
-              destructive
-                ? "text-red-600 dark:text-red-400"
-                : "text-malachite-600 dark:text-malachite-400"
-            }
-          />
-        </div>
-        <p className="text-sm text-gray-600 dark:text-gray-300 leading-relaxed pt-1">
-          {message}
-        </p>
-      </div>
+      <p className="fr-mb-3w">{message}</p>
 
-      <div className="flex justify-end gap-2">
-        <Button variant="ghost" onClick={onClose}>
-          {cancelLabel}
-        </Button>
-        <Button
-          variant={destructive ? "danger" : "primary"}
-          onClick={() => {
-            onConfirm();
-            onClose();
-          }}
-        >
-          {confirmLabel}
-        </Button>
-      </div>
+      <ul className="fr-btns-group fr-btns-group--right fr-btns-group--inline-reverse fr-btns-group--inline-lg">
+        <li>
+          <Button
+            variant={destructive ? "danger" : "primary"}
+            onClick={() => {
+              onConfirm();
+              onClose();
+            }}
+          >
+            {confirmLabel}
+          </Button>
+        </li>
+        <li>
+          <Button variant="secondary" onClick={onClose}>
+            {cancelLabel}
+          </Button>
+        </li>
+      </ul>
     </Modal>
   );
 }