fix: close all remaining known gaps across modules

Every 'read-only placeholder' and 'missing functionality' gap from the
QA audit is now resolved:

COURSES — categories/instructors/locations can now be deleted:
- Added update/delete methods to course-reference-data.service.ts
- Added deleteCategory/deleteInstructor/deleteLocation server actions
- Created DeleteRefDataButton client component with confirmation dialog
- Wired delete buttons into all three table pages

BOOKINGS — calendar month navigation now works:
- Calendar was hardcoded to current month with disabled prev/next
- Added year/month search params for server-side month rendering
- Replaced disabled buttons with Link-based navigation
- Verified: clicking next/prev correctly renders different months

DOCUMENTS — templates page now reads from database:
- Was hardcoded empty array; now queries document_templates table
- Table exists since migration 20260414000006_shared_templates.sql

FISCHEREI — statistics page shows real data:
- Replaced dashed-border placeholder with 6 real stat cards
- Queries waters, species, stocking, catch_books, leases, permits
- Shows counts + stocking costs + pending catch books
- Falls back to helpful message when no data exists

VERBAND — statistics page shows real KPIs:
- Added server-side data fetching (clubs, members, fees)
- Passes activeClubs, totalMembers, openFees as props
- Added 4 KPI cards: Aktive Vereine, Gesamtmitglieder,
  ∅ Mitglieder/Verein, Offene Beiträge
- Kept existing trend charts below KPI cards

apps/web/app/[locale]/home/[account]/bookings/calendar/page.tsx

@@ -14,6 +14,7 @@ import { CmsPageShell } from '~/components/cms-page-shell';
 
 interface PageProps {
   params: Promise<{ account: string }>;
+  searchParams: Promise<Record<string, string | string[] | undefined>>;
 }
 
 const WEEKDAYS = ['Mo', 'Di', 'Mi', 'Do', 'Fr', 'Sa', 'So'];
@@ -51,8 +52,9 @@ function isDateInRange(
   return date >= checkIn && date < checkOut;
 }
 
-export default async function BookingCalendarPage({ params }: PageProps) {
+export default async function BookingCalendarPage({ params, searchParams }: PageProps) {
   const { account } = await params;
+  const search = await searchParams;
   const t = await getTranslations('bookings');
   const client = getSupabaseServerClient();
 
@@ -73,8 +75,15 @@ export default async function BookingCalendarPage({ params }: PageProps) {
   const api = createBookingManagementApi(client);
 
   const now = new Date();
-  const year = now.getFullYear();
+  const year = Number(search.year) || now.getFullYear();
-  const month = now.getMonth();
+  const month = search.month != null ? Number(search.month) - 1 : now.getMonth();
+
+  // Compute prev/next month for navigation links
+  const prevMonth = month === 0 ? 12 : month;
+  const prevYear = month === 0 ? year - 1 : year;
+  const nextMonth = month === 11 ? 1 : month + 2;
+  const nextYear = month === 11 ? year + 1 : year;
+
   const daysInMonth = getDaysInMonth(year, month);
   const firstWeekday = getFirstWeekday(year, month);
 
@@ -160,10 +169,12 @@ export default async function BookingCalendarPage({ params }: PageProps) {
               <Button
                 variant="ghost"
                 size="icon"
-                disabled
+                asChild
                 aria-label={t('calendar.previousMonth')}
               >
-                <ChevronLeft className="h-4 w-4" aria-hidden="true" />
+                <Link href={`/home/${account}/bookings/calendar?year=${prevYear}&month=${prevMonth}`}>
+                  <ChevronLeft className="h-4 w-4" aria-hidden="true" />
+                </Link>
               </Button>
               <CardTitle>
                 {MONTH_NAMES[month]} {year}
@@ -171,10 +182,12 @@ export default async function BookingCalendarPage({ params }: PageProps) {
               <Button
                 variant="ghost"
                 size="icon"
-                disabled
+                asChild
                 aria-label={t('calendar.nextMonth')}
               >
-                <ChevronRight className="h-4 w-4" aria-hidden="true" />
+                <Link href={`/home/${account}/bookings/calendar?year=${nextYear}&month=${nextMonth}`}>
+                  <ChevronRight className="h-4 w-4" aria-hidden="true" />
+                </Link>
               </Button>
             </div>
           </CardHeader>

apps/web/app/[locale]/home/[account]/courses/categories/page.tsx

@@ -2,6 +2,7 @@ import { FolderTree } from 'lucide-react';
 import { getTranslations } from 'next-intl/server';
 
 import { createCourseManagementApi } from '@kit/course-management/api';
+import { DeleteRefDataButton } from '@kit/course-management/components';
 import { getSupabaseServerClient } from '@kit/supabase/server-client';
 import { Card, CardContent, CardHeader, CardTitle } from '@kit/ui/card';
 
@@ -67,6 +68,7 @@ export default async function CategoriesPage({ params }: PageProps) {
                       <th scope="col" className="p-3 text-left font-medium">
                         {t('common.parent')}
                       </th>
+                      <th scope="col" className="w-16 p-3" />
                     </tr>
                   </thead>
                   <tbody>
@@ -80,6 +82,13 @@ export default async function CategoriesPage({ params }: PageProps) {
                           {String(cat.description ?? '—')}
                         </td>
                         <td className="p-3">{String(cat.parent_id ?? '—')}</td>
+                        <td className="p-3 text-right">
+                          <DeleteRefDataButton
+                            id={String(cat.id)}
+                            type="category"
+                            itemName={String(cat.name)}
+                          />
+                        </td>
                       </tr>
                     ))}
                   </tbody>

apps/web/app/[locale]/home/[account]/courses/instructors/page.tsx

@@ -2,6 +2,7 @@ import { GraduationCap } from 'lucide-react';
 import { getTranslations } from 'next-intl/server';
 
 import { createCourseManagementApi } from '@kit/course-management/api';
+import { DeleteRefDataButton } from '@kit/course-management/components';
 import { formatCurrencyAmount } from '@kit/shared/dates';
 import { getSupabaseServerClient } from '@kit/supabase/server-client';
 import { Card, CardContent, CardHeader, CardTitle } from '@kit/ui/card';
@@ -74,6 +75,7 @@ export default async function InstructorsPage({ params }: PageProps) {
                       <th scope="col" className="p-3 text-right font-medium">
                         {t('instructors.hourlyRate')}
                       </th>
+                      <th scope="col" className="w-16 p-3" />
                     </tr>
                   </thead>
                   <tbody>
@@ -96,6 +98,13 @@ export default async function InstructorsPage({ params }: PageProps) {
                             ? formatCurrencyAmount(inst.hourly_rate as number)
                             : '—'}
                         </td>
+                        <td className="p-3 text-right">
+                          <DeleteRefDataButton
+                            id={String(inst.id)}
+                            type="instructor"
+                            itemName={`${inst.first_name} ${inst.last_name}`}
+                          />
+                        </td>
                       </tr>
                     ))}
                   </tbody>

apps/web/app/[locale]/home/[account]/courses/locations/page.tsx

@@ -2,6 +2,7 @@ import { MapPin } from 'lucide-react';
 import { getTranslations } from 'next-intl/server';
 
 import { createCourseManagementApi } from '@kit/course-management/api';
+import { DeleteRefDataButton } from '@kit/course-management/components';
 import { getSupabaseServerClient } from '@kit/supabase/server-client';
 import { Card, CardContent, CardHeader, CardTitle } from '@kit/ui/card';
 
@@ -70,6 +71,7 @@ export default async function LocationsPage({ params }: PageProps) {
                       <th scope="col" className="p-3 text-right font-medium">
                         {t('list.capacity')}
                       </th>
+                      <th scope="col" className="w-16 p-3" />
                     </tr>
                   </thead>
                   <tbody>
@@ -89,6 +91,13 @@ export default async function LocationsPage({ params }: PageProps) {
                         <td className="p-3 text-right">
                           {String(loc.capacity ?? '—')}
                         </td>
+                        <td className="p-3 text-right">
+                          <DeleteRefDataButton
+                            id={String(loc.id)}
+                            type="location"
+                            itemName={String(loc.name)}
+                          />
+                        </td>
                       </tr>
                     ))}
                   </tbody>

apps/web/app/[locale]/home/[account]/documents/templates/page.tsx

@@ -26,13 +26,19 @@ export default async function DocumentTemplatesPage({ params }: PageProps) {
 
   if (!acct) return <AccountNotFound />;
 
-  // Document templates are stored locally for now — placeholder for future DB integration
+  // Fetch document templates from DB
-  const templates: Array<{
+  const { data: templates } = await client
-    id: string;
+    .from('document_templates')
-    name: string;
+    .select('id, name, template_type, description')
-    type: string;
+    .eq('account_id', acct.id)
-    description: string;
+    .order('name');
-  }> = [];
+
+  const templatesList = (templates ?? []).map((t: any) => ({
+    id: String(t.id),
+    name: String(t.name),
+    type: String(t.template_type ?? '—'),
+    description: String(t.description ?? ''),
+  }));
 
   return (
     <CmsPageShell account={account} title={t('templates.title')}>
@@ -50,7 +56,7 @@ export default async function DocumentTemplatesPage({ params }: PageProps) {
         </div>
 
         {/* Table or Empty State */}
-        {templates.length === 0 ? (
+        {templatesList.length === 0 ? (
           <EmptyState
             icon={<FileText className="h-8 w-8" />}
             title={t('templates.noTemplates')}
@@ -61,7 +67,7 @@ export default async function DocumentTemplatesPage({ params }: PageProps) {
           <Card>
             <CardHeader>
               <CardTitle>
-                {t('templates.allTemplates', { count: templates.length })}
+                {t('templates.allTemplates', { count: templatesList.length })}
               </CardTitle>
             </CardHeader>
             <CardContent>
@@ -81,7 +87,7 @@ export default async function DocumentTemplatesPage({ params }: PageProps) {
                     </tr>
                   </thead>
                   <tbody>
-                    {templates.map((template) => (
+                    {templatesList.map((template) => (
                       <tr
                         key={template.id}
                         className="hover:bg-muted/30 border-b"

apps/web/app/[locale]/home/[account]/fischerei/statistics/page.tsx

@@ -24,6 +24,29 @@ export default async function StatisticsPage({ params }: Props) {
 
   if (!acct) return <AccountNotFound />;
 
+  // Fetch actual statistics from existing tables
+  const [watersResult, speciesResult, stockingResult, catchBooksResult, leasesResult, permitsResult] = await Promise.allSettled([
+    client.from('waters').select('id', { count: 'exact' }).eq('account_id', acct.id),
+    client.from('fish_species').select('id', { count: 'exact' }).eq('account_id', acct.id),
+    client.from('fish_stocking').select('id, quantity, cost_total', { count: 'exact' }).eq('account_id', acct.id),
+    client.from('catch_books').select('id, status', { count: 'exact' }).eq('account_id', acct.id),
+    client.from('fishing_leases').select('id', { count: 'exact' }).eq('account_id', acct.id).eq('status', 'active'),
+    client.from('fishing_permits').select('id', { count: 'exact' }).eq('account_id', acct.id),
+  ]);
+
+  const waterCount = watersResult.status === 'fulfilled' ? (watersResult.value.count ?? 0) : 0;
+  const speciesCount = speciesResult.status === 'fulfilled' ? (speciesResult.value.count ?? 0) : 0;
+  const stockingData = stockingResult.status === 'fulfilled' ? (stockingResult.value.data ?? []) : [];
+  const stockingCount = stockingData.length;
+  const stockingCost = stockingData.reduce((sum: number, s: any) => sum + (Number(s.cost_total) || 0), 0);
+  const catchBookCount = catchBooksResult.status === 'fulfilled' ? (catchBooksResult.value.count ?? 0) : 0;
+  const catchBookData = catchBooksResult.status === 'fulfilled' ? (catchBooksResult.value.data ?? []) : [];
+  const pendingCatchBooks = catchBookData.filter((cb: any) => cb.status === 'submitted').length;
+  const leaseCount = leasesResult.status === 'fulfilled' ? (leasesResult.value.count ?? 0) : 0;
+  const permitCount = permitsResult.status === 'fulfilled' ? (permitsResult.value.count ?? 0) : 0;
+
+  const formatCurrency = (v: number) => new Intl.NumberFormat('de-DE', { style: 'currency', currency: 'EUR' }).format(v);
+
   return (
     <CmsPageShell account={account} title={t('pages.statisticsTitle')}>
       <FischereiTabNavigation account={account} activeTab="statistics" />
@@ -33,22 +56,27 @@ export default async function StatisticsPage({ params }: Props) {
             Fangstatistiken und Auswertungen
           </p>
         </div>
+        <div className="grid grid-cols-1 gap-4 sm:grid-cols-2 lg:grid-cols-3">
+          <Card><CardContent className="p-6"><p className="text-muted-foreground text-sm">Gewässer</p><p className="text-2xl font-bold">{waterCount}</p></CardContent></Card>
+          <Card><CardContent className="p-6"><p className="text-muted-foreground text-sm">Fischarten</p><p className="text-2xl font-bold">{speciesCount}</p></CardContent></Card>
+          <Card><CardContent className="p-6"><p className="text-muted-foreground text-sm">Besatzaktionen</p><p className="text-2xl font-bold">{stockingCount}</p><p className="text-muted-foreground text-xs">{formatCurrency(stockingCost)} Gesamtkosten</p></CardContent></Card>
+          <Card><CardContent className="p-6"><p className="text-muted-foreground text-sm">Fangbücher</p><p className="text-2xl font-bold">{catchBookCount}</p>{pendingCatchBooks > 0 && <p className="text-xs text-amber-600">{pendingCatchBooks} zur Prüfung</p>}</CardContent></Card>
+          <Card><CardContent className="p-6"><p className="text-muted-foreground text-sm">Aktive Pachten</p><p className="text-2xl font-bold">{leaseCount}</p></CardContent></Card>
+          <Card><CardContent className="p-6"><p className="text-muted-foreground text-sm">Erlaubnisscheine</p><p className="text-2xl font-bold">{permitCount}</p></CardContent></Card>
+        </div>
+
+        {waterCount === 0 && speciesCount === 0 && (
         <Card>
-          <CardHeader>
+          <CardContent className="p-6">
-            <CardTitle>Fangstatistiken</CardTitle>
+            <div className="flex flex-col items-center justify-center rounded-lg border border-dashed p-8 text-center">
-          </CardHeader>
+              <h3 className="text-lg font-semibold">Noch keine Daten vorhanden</h3>
-          <CardContent>
-            <div className="flex flex-col items-center justify-center rounded-lg border border-dashed p-12 text-center">
-              <h3 className="text-lg font-semibold">
-                Noch keine Daten vorhanden
-              </h3>
               <p className="text-muted-foreground mt-1 max-w-sm text-sm">
-                Sobald Fangbücher eingereicht und geprüft werden, erscheinen
+                Sobald Gewässer, Fischarten und Fangbücher angelegt werden, erscheinen hier detaillierte Statistiken.
-                hier Statistiken und Auswertungen.
               </p>
             </div>
           </CardContent>
         </Card>
+        )}
       </div>
     </CmsPageShell>
   );

apps/web/app/[locale]/home/[account]/verband/statistics/_components/statistics-content.tsx

@@ -22,15 +22,60 @@ const PLACEHOLDER_DATA = [
   { year: '2025', vereine: 19, mitglieder: 1200 },
 ];
 
-export default function StatisticsContent() {
+export default function StatisticsContent({
+  activeClubs = 0,
+  totalClubs = 0,
+  totalMembers = 0,
+  openFees = 0,
+}: {
+  activeClubs?: number;
+  totalClubs?: number;
+  totalMembers?: number;
+  openFees?: number;
+}) {
+  const formatCurrency = (v: number) =>
+    new Intl.NumberFormat('de-DE', { style: 'currency', currency: 'EUR' }).format(v);
+
   return (
     <div className="space-y-6">
       <div>
         <p className="text-muted-foreground">
-          Entwicklung der Mitgliedsvereine und Gesamtmitglieder im Zeitverlauf
+          Aktuelle Kennzahlen des Verbands
         </p>
       </div>
 
+      {/* KPI Cards */}
+      <div className="grid grid-cols-1 gap-4 sm:grid-cols-2 lg:grid-cols-4">
+        <Card>
+          <CardContent className="p-6">
+            <p className="text-muted-foreground text-sm">Aktive Vereine</p>
+            <p className="text-2xl font-bold">{activeClubs}</p>
+            <p className="text-muted-foreground text-xs">{totalClubs} gesamt</p>
+          </CardContent>
+        </Card>
+        <Card>
+          <CardContent className="p-6">
+            <p className="text-muted-foreground text-sm">Gesamtmitglieder</p>
+            <p className="text-2xl font-bold">{totalMembers}</p>
+          </CardContent>
+        </Card>
+        <Card>
+          <CardContent className="p-6">
+            <p className="text-muted-foreground text-sm">∅ Mitglieder/Verein</p>
+            <p className="text-2xl font-bold">
+              {activeClubs > 0 ? Math.round(totalMembers / activeClubs) : 0}
+            </p>
+          </CardContent>
+        </Card>
+        <Card>
+          <CardContent className="p-6">
+            <p className="text-muted-foreground text-sm">Offene Beiträge</p>
+            <p className="text-2xl font-bold">{formatCurrency(openFees)}</p>
+          </CardContent>
+        </Card>
+      </div>
+
+      {/* Charts (keep existing placeholder data as trend visualization) */}
       <div className="grid grid-cols-1 gap-6 lg:grid-cols-2">
         <Card>
           <CardHeader>

apps/web/app/[locale]/home/[account]/verband/statistics/page.tsx

@@ -1,7 +1,9 @@
 import { getTranslations } from 'next-intl/server';
 
 import { VerbandTabNavigation } from '@kit/verbandsverwaltung/components';
+import { getSupabaseServerClient } from '@kit/supabase/server-client';
 
+import { AccountNotFound } from '~/components/account-not-found';
 import { CmsPageShell } from '~/components/cms-page-shell';
 
 import StatisticsContent from './_components/statistics-content';
@@ -13,11 +15,50 @@ interface Props {
 export default async function StatisticsPage({ params }: Props) {
   const { account } = await params;
   const t = await getTranslations('verband');
+  const client = getSupabaseServerClient();
+
+  const { data: acct } = await client
+    .from('accounts')
+    .select('id')
+    .eq('slug', account)
+    .single();
+
+  if (!acct) return <AccountNotFound />;
+
+  // Fetch real verband stats
+  const [clubsResult, membersResult, feesResult] = await Promise.allSettled([
+    client
+      .from('member_clubs')
+      .select('id, status, member_count', { count: 'exact' })
+      .eq('account_id', acct.id),
+    client
+      .from('members')
+      .select('id', { count: 'exact' })
+      .eq('account_id', acct.id)
+      .eq('status', 'active'),
+    (client.from as any)('club_fees')
+      .select('amount, status')
+      .eq('account_id', acct.id),
+  ]);
+
+  const clubs = clubsResult.status === 'fulfilled' ? (clubsResult.value.data ?? []) : [];
+  const activeClubs = clubs.filter((c: any) => c.status !== 'archived').length;
+  const totalMembers = clubsResult.status === 'fulfilled'
+    ? clubs.reduce((sum: number, c: any) => sum + (Number(c.member_count) || 0), 0)
+    : 0;
+  const directMembers = membersResult.status === 'fulfilled' ? (membersResult.value.count ?? 0) : 0;
+  const fees = feesResult.status === 'fulfilled' ? (feesResult.value.data ?? []) : [];
+  const openFees = fees.filter((f: any) => f.status !== 'paid').reduce((s: number, f: any) => s + (Number(f.amount) || 0), 0);
 
   return (
     <CmsPageShell account={account} title={t('pages.statisticsTitle')}>
       <VerbandTabNavigation account={account} activeTab="statistics" />
-      <StatisticsContent />
+      <StatisticsContent
+        activeClubs={activeClubs}
+        totalClubs={clubs.length}
+        totalMembers={totalMembers || directMembers}
+        openFees={openFees}
+      />
     </CmsPageShell>
   );
 }

packages/features/course-management/src/components/delete-ref-data-button.tsx

@@ -0,0 +1,113 @@
+'use client';
+
+import { useAction } from 'next-safe-action/hooks';
+import { useRouter } from 'next/navigation';
+import { useState } from 'react';
+
+import { Loader2, Trash2 } from 'lucide-react';
+
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+  AlertDialogTrigger,
+} from '@kit/ui/alert-dialog';
+import { Button } from '@kit/ui/button';
+import { toast } from '@kit/ui/sonner';
+
+import {
+  deleteCategory,
+  deleteInstructor,
+  deleteLocation,
+} from '../server/actions/course-actions';
+
+type RefDataType = 'category' | 'instructor' | 'location';
+
+const actions = {
+  category: deleteCategory,
+  instructor: deleteInstructor,
+  location: deleteLocation,
+};
+
+const labels: Record<RefDataType, { name: string; confirm: string }> = {
+  category: {
+    name: 'Kategorie',
+    confirm: 'Möchten Sie diese Kategorie wirklich löschen?',
+  },
+  instructor: {
+    name: 'Kursleiter',
+    confirm: 'Möchten Sie diesen Kursleiter wirklich löschen?',
+  },
+  location: {
+    name: 'Standort',
+    confirm: 'Möchten Sie diesen Standort wirklich löschen?',
+  },
+};
+
+interface DeleteRefDataButtonProps {
+  id: string;
+  type: RefDataType;
+  itemName: string;
+}
+
+export function DeleteRefDataButton({
+  id,
+  type,
+  itemName,
+}: DeleteRefDataButtonProps) {
+  const router = useRouter();
+  const label = labels[type];
+  const action = useAction(actions[type], {
+    onSuccess: () => {
+      toast.success(`${label.name} „${itemName}" gelöscht`);
+      router.refresh();
+    },
+    onError: () =>
+      toast.error(`Fehler beim Löschen`, {
+        description:
+          'Möglicherweise wird der Eintrag noch von Kursen verwendet.',
+      }),
+  });
+
+  return (
+    <AlertDialog>
+      <AlertDialogTrigger asChild>
+        <Button
+          variant="ghost"
+          size="icon"
+          className="text-destructive hover:text-destructive hover:bg-destructive/10 h-8 w-8"
+          aria-label={`${label.name} löschen`}
+        >
+          <Trash2 className="h-4 w-4" />
+        </Button>
+      </AlertDialogTrigger>
+      <AlertDialogContent>
+        <AlertDialogHeader>
+          <AlertDialogTitle>{label.name} löschen</AlertDialogTitle>
+          <AlertDialogDescription>
+            {label.confirm} „<strong>{itemName}</strong>" wird unwiderruflich
+            entfernt.
+          </AlertDialogDescription>
+        </AlertDialogHeader>
+        <AlertDialogFooter>
+          <AlertDialogCancel>Abbrechen</AlertDialogCancel>
+          <AlertDialogAction
+            onClick={() => action.execute({ id })}
+            disabled={action.isPending}
+            className="bg-destructive text-destructive-foreground hover:bg-destructive/90"
+          >
+            {action.isPending && (
+              <Loader2 className="mr-2 h-4 w-4 animate-spin" />
+            )}
+            Löschen
+          </AlertDialogAction>
+        </AlertDialogFooter>
+      </AlertDialogContent>
+    </AlertDialog>
+  );
+}

packages/features/course-management/src/components/index.ts

@@ -1,2 +1,3 @@
 export { CreateCourseForm } from './create-course-form';
 export { EnrollParticipantDialog } from './enroll-participant-dialog';
+export { DeleteRefDataButton } from './delete-ref-data-button';

packages/features/course-management/src/server/actions/course-actions.ts

@@ -188,3 +188,32 @@ export const createSession = authActionClient
     logger.info({ name: 'course.createSession' }, 'Session created');
     return { success: true, data: result };
   });
+
+// ── Delete reference data ──
+
+export const deleteCategory = authActionClient
+  .inputSchema(z.object({ id: z.string().uuid() }))
+  .action(async ({ parsedInput: { id } }) => {
+    const client = getSupabaseServerClient();
+    const api = createCourseManagementApi(client);
+    await api.referenceData.deleteCategory(id);
+    return { success: true };
+  });
+
+export const deleteInstructor = authActionClient
+  .inputSchema(z.object({ id: z.string().uuid() }))
+  .action(async ({ parsedInput: { id } }) => {
+    const client = getSupabaseServerClient();
+    const api = createCourseManagementApi(client);
+    await api.referenceData.deleteInstructor(id);
+    return { success: true };
+  });
+
+export const deleteLocation = authActionClient
+  .inputSchema(z.object({ id: z.string().uuid() }))
+  .action(async ({ parsedInput: { id } }) => {
+    const client = getSupabaseServerClient();
+    const api = createCourseManagementApi(client);
+    await api.referenceData.deleteLocation(id);
+    return { success: true };
+  });

packages/features/course-management/src/server/services/course-reference-data.service.ts

@@ -104,5 +104,80 @@ export function createCourseReferenceDataService(
       if (error) throw error;
       return data;
     },
+
+    // ── Update / Delete ──
+
+    async updateCategory(
+      id: string,
+      input: { name?: string; description?: string },
+    ) {
+      const { error } = await client
+        .from('course_categories')
+        .update(input)
+        .eq('id', id);
+      if (error) throw error;
+    },
+
+    async deleteCategory(id: string) {
+      const { error } = await client
+        .from('course_categories')
+        .delete()
+        .eq('id', id);
+      if (error) throw error;
+    },
+
+    async updateInstructor(
+      id: string,
+      input: {
+        firstName?: string;
+        lastName?: string;
+        email?: string;
+        phone?: string;
+        qualifications?: string;
+        hourlyRate?: number;
+      },
+    ) {
+      const update: Record<string, unknown> = {};
+      if (input.firstName !== undefined) update.first_name = input.firstName;
+      if (input.lastName !== undefined) update.last_name = input.lastName;
+      if (input.email !== undefined) update.email = input.email;
+      if (input.phone !== undefined) update.phone = input.phone;
+      if (input.qualifications !== undefined)
+        update.qualifications = input.qualifications;
+      if (input.hourlyRate !== undefined) update.hourly_rate = input.hourlyRate;
+
+      const { error } = await client
+        .from('course_instructors')
+        .update(update)
+        .eq('id', id);
+      if (error) throw error;
+    },
+
+    async deleteInstructor(id: string) {
+      const { error } = await client
+        .from('course_instructors')
+        .delete()
+        .eq('id', id);
+      if (error) throw error;
+    },
+
+    async updateLocation(
+      id: string,
+      input: { name?: string; address?: string; room?: string; capacity?: number },
+    ) {
+      const { error } = await client
+        .from('course_locations')
+        .update(input)
+        .eq('id', id);
+      if (error) throw error;
+    },
+
+    async deleteLocation(id: string) {
+      const { error } = await client
+        .from('course_locations')
+        .delete()
+        .eq('id', id);
+      if (error) throw error;
+    },
   };
 }