refactor: add SessionPageHeader and apply to all 6 session detail pages

- Create SessionPageHeader component (breadcrumb + editable title + collaborator + badges + date)
- Embed UPDATE_FN map internally, keyed by workshopType — no prop drilling
- Replace duplicated header blocks in sessions, motivators, year-review, weather, weekly-checkin, gif-mood

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

src/app/gif-mood/[id]/page.tsx

@@ -1,11 +1,9 @@
 import { notFound } from 'next/navigation';
-import Link from 'next/link';
 import { auth } from '@/lib/auth';
-import { getWorkshop, getSessionsTabUrl } from '@/lib/workshops';
 import { getGifMoodSessionById } from '@/services/gif-mood';
 import { getUserTeams } from '@/services/teams';
 import { GifMoodBoard, GifMoodLiveWrapper } from '@/components/gif-mood';
-import { Badge, EditableGifMoodTitle } from '@/components/ui';
+import { Badge, SessionPageHeader } from '@/components/ui';
 
 interface GifMoodSessionPageProps {
   params: Promise<{ id: string }>;
@@ -29,41 +27,16 @@ export default async function GifMoodSessionPage({ params }: GifMoodSessionPageP
 
   return (
     <main className="mx-auto max-w-7xl px-4">
-      {/* Header */}
-      <div className="mb-8">
-        <div className="flex items-center gap-2 text-sm text-muted mb-2">
-          <Link href={getSessionsTabUrl('gif-mood')} className="hover:text-foreground">
-            {getWorkshop('gif-mood').labelShort}
-          </Link>
-          <span>/</span>
-          <span className="text-foreground">{session.title}</span>
-          {!session.isOwner && (
-            <Badge variant="accent" className="ml-2">
-              Partagé par {session.user.name || session.user.email}
-            </Badge>
-          )}
-        </div>
-
-        <div className="flex items-start justify-between">
-          <div>
-            <EditableGifMoodTitle
-              sessionId={session.id}
-              initialTitle={session.title}
-              canEdit={session.canEdit}
-            />
-          </div>
-          <div className="flex items-center gap-3">
-            <Badge variant="primary">{session.items.length} GIFs</Badge>
-            <span className="text-sm text-muted">
-              {new Date(session.date).toLocaleDateString('fr-FR', {
-                day: 'numeric',
-                month: 'long',
-                year: 'numeric',
-              })}
-            </span>
-          </div>
-        </div>
-      </div>
+      <SessionPageHeader
+        workshopType="gif-mood"
+        sessionId={session.id}
+        sessionTitle={session.title}
+        isOwner={session.isOwner}
+        canEdit={session.canEdit}
+        ownerUser={session.user}
+        date={session.date}
+        badges={<Badge variant="primary">{session.items.length} GIFs</Badge>}
+      />
 
       {/* Live Wrapper + Board */}
       <GifMoodLiveWrapper