refactor(members): consolidate Platform Admin + Org members into shared useMembers

- useMembers.ts gains a scope param ('organisation' | 'platform') on list,
  invite, update-role, and remove; endpoints branch accordingly.
- Platform Admin's [id].vue now consumes useMembers via scope='platform';
  deleted the duplicated useInviteOrganisationMember / useRemoveOrganisationMember
  / useUpdateOrganisationMemberRole helpers from useAdmin.ts.
- Deduplicated InviteMemberPayload / UpdateMemberRolePayload / AdminOrganisationMember
  from types/admin.ts; Member is now the canonical type.
- SettingsMembers.vue and EditMemberRoleDialog.vue removed (no remaining imports).
- InviteMemberDialog accepts an optional scope prop and is restricted to the
  two organisation-level roles matching the /members UX.

apps/app/components.d.ts

@@ -67,6 +67,7 @@ declare module 'vue' {
     EventMetricCards: typeof import('./src/components/events/EventMetricCards.vue')['default']
     EventTabsNav: typeof import('./src/components/events/EventTabsNav.vue')['default']
     I18n: typeof import('./src/@core/components/I18n.vue')['default']
+    ImageUploadField: typeof import('./src/components/common/ImageUploadField.vue')['default']
     ImpersonateDialog: typeof import('./src/components/platform/ImpersonateDialog.vue')['default']
     ImpersonationBanner: typeof import('./src/components/platform/ImpersonationBanner.vue')['default']
     ImportFromEventDialog: typeof import('./src/components/event/ImportFromEventDialog.vue')['default']
@@ -80,6 +81,7 @@ declare module 'vue' {
     Notifications: typeof import('./src/@core/components/Notifications.vue')['default']
     NotificationsTab: typeof import('./src/components/account-settings/NotificationsTab.vue')['default']
     OrganisationSwitcher: typeof import('./src/components/layout/OrganisationSwitcher.vue')['default']
+    PasswordRequirements: typeof import('./src/components/auth/PasswordRequirements.vue')['default']
     PaymentProvidersDialog: typeof import('./src/components/dialogs/PaymentProvidersDialog.vue')['default']
     PersonDetailPanel: typeof import('./src/components/persons/PersonDetailPanel.vue')['default']
     PersonTagsTab: typeof import('./src/components/organisation/PersonTagsTab.vue')['default']