Corrige le Realtime qui ne diffusait aucun événement à travers l'app

Les canaux Realtime (Char, Gardien, classement, journal, calendrier,
Icare) s'abonnaient juste après createClient(), avant que la session
ne soit chargée de façon asynchrone — le canal rejoignait donc
Supabase en rôle "anon" au lieu de "authenticated", et les policies
RLS "to authenticated" bloquaient silencieusement tous les événements
(l'abonnement lui-même réussissait, ce qui masquait le problème).

Ajoute waitForRealtimeAuth() dans src/lib/supabase/client.ts, qui
attend la session et pousse explicitement le token avant de
s'abonner. Vérifié avec deux sessions navigateur distinctes : les
changements se propagent maintenant réellement sans rechargement.

src/app/leaderboard/leaderboard-view.tsx

@@ -1,7 +1,7 @@
 "use client";
 
 import { useEffect, useMemo, useRef, useState } from "react";
-import { createClient } from "@/lib/supabase/client";
+import { createClient, waitForRealtimeAuth } from "@/lib/supabase/client";
 import { Avatar } from "@/components/avatar";
 import { Podium } from "@/components/podium";
 import { JudgePointControls } from "@/components/judge-point-controls";
@@ -47,34 +47,41 @@ export function LeaderboardView({
 
   useEffect(() => {
     const supabase = createClient();
-    const channel = supabase
-      .channel("leaderboard-profiles")
-      .on(
-        "postgres_changes",
-        { event: "*", schema: "public", table: "profiles" },
-        (payload) => {
-          if (payload.eventType === "DELETE") return;
-          const row = payload.new as Profile;
+    let channel: ReturnType<typeof supabase.channel> | null = null;
+    let cancelled = false;
 
-          setProfiles((current) => {
-            const exists = current.some((p) => p.id === row.id);
-            return exists
-              ? current.map((p) => (p.id === row.id ? { ...p, ...row } : p))
-              : [...current, row];
-          });
+    waitForRealtimeAuth(supabase).then(() => {
+      if (cancelled) return;
+      channel = supabase
+        .channel("leaderboard-profiles")
+        .on(
+          "postgres_changes",
+          { event: "*", schema: "public", table: "profiles" },
+          (payload) => {
+            if (payload.eventType === "DELETE") return;
+            const row = payload.new as Profile;
 
-          const previousPoints = pointsRef.current.get(row.id);
-          if (previousPoints !== undefined && previousPoints !== row.points) {
-            setFlashingId(row.id);
-            setTimeout(() => setFlashingId((current) => (current === row.id ? null : current)), 900);
-          }
-          pointsRef.current.set(row.id, row.points);
-        },
-      )
-      .subscribe();
+            setProfiles((current) => {
+              const exists = current.some((p) => p.id === row.id);
+              return exists
+                ? current.map((p) => (p.id === row.id ? { ...p, ...row } : p))
+                : [...current, row];
+            });
+
+            const previousPoints = pointsRef.current.get(row.id);
+            if (previousPoints !== undefined && previousPoints !== row.points) {
+              setFlashingId(row.id);
+              setTimeout(() => setFlashingId((current) => (current === row.id ? null : current)), 900);
+            }
+            pointsRef.current.set(row.id, row.points);
+          },
+        )
+        .subscribe();
+    });
 
     return () => {
-      supabase.removeChannel(channel);
+      cancelled = true;
+      if (channel) supabase.removeChannel(channel);
     };
   }, []);