fix(organisation): restore dashboard types dropped during commit split

Add OrganisationMember (met avatar + joined_at), ActivityLogEntry en
OrganisationDashboardStats interfaces die door de pagina en composable
worden gebruikt. Deze hoorden in de dashboard-commit maar vielen uit
door een staging-split.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/app/src/types/organisation.ts

@@ -21,7 +21,33 @@ export interface OrganisationMember {
   id: string
   name: string
   email: string
+  avatar_url: string | null
   role: string
+  joined_at: string | null
+}
+
+export interface ActivityLogEntry {
+  id: string
+  description: string
+  causer_name: string | null
+  causer_avatar_url: string | null
+  subject_type: string | null
+  subject_id: string | null
+  properties: {
+    attributes?: Record<string, unknown>
+    old?: Record<string, unknown>
+  }
+  created_at: string | null
+}
+
+export interface OrganisationDashboardStats {
+  members_count: number
+  events_count: number
+  events_by_status: Record<string, number>
+  active_events_count: number
+  persons_count: number
+  top_members: OrganisationMember[]
+  recent_activity: ActivityLogEntry[]
 }
 
 export interface UpdateOrganisationPayload {