fix: clean up dangling FK references before deleting a user

Resolves FOREIGN KEY constraint failed (500) on DELETE /api/admin/users/:id
and DELETE /api/auth/me when the target user had rows in trip_members.invited_by,
share_tokens.created_by, budget_items.paid_by_user_id, journeys.user_id,
journey_entries.author_id, journey_contributors.user_id, or
journey_share_tokens.created_by — none of which had ON DELETE clauses.

Introduces deleteUserCompletely() in userCleanupService.ts which wraps all
cleanup and the final DELETE FROM users in a single transaction. Both
adminService.deleteUser and authService.deleteAccount now call it instead of
the bare DELETE. Tests ADMIN-005b and AUTH-040 cover all reference types
including notification sender/recipient and notice dismissals.

server/src/services/adminService.ts

@@ -8,6 +8,7 @@ import { updateJwtSecret } from '../config';
 import { maybe_encrypt_api_key, decrypt_api_key } from './apiKeyCrypto';
 import { getAllPermissions, savePermissions as savePerms, PERMISSION_ACTIONS } from './permissions';
 import { revokeUserSessions, revokeUserSessionsForClient } from '../mcp';
+import { deleteUserCompletely } from './userCleanupService';
 import { validatePassword } from './passwordPolicy';
 import { getPhotoProviderConfig } from './memories/helpersService';
 import { send as sendNotification } from './notificationService';
@@ -170,7 +171,7 @@ export function deleteUser(id: string, currentUserId: number) {
   const userToDel = db.prepare('SELECT id, email FROM users WHERE id = ?').get(id) as { id: number; email: string } | undefined;
   if (!userToDel) return { error: 'User not found', status: 404 };
 
-  db.prepare('DELETE FROM users WHERE id = ?').run(id);
+  deleteUserCompletely(userToDel.id);
   return { email: userToDel.email };
 }
 

server/src/services/authService.ts

@@ -15,6 +15,7 @@ import { decrypt_api_key, maybe_encrypt_api_key, encrypt_api_key } from './apiKe
 import { createEphemeralToken } from './ephemeralTokens';
 import { revokeUserSessions } from '../mcp';
 import { startTripReminders } from '../scheduler';
+import { deleteUserCompletely } from './userCleanupService';
 import { verifyJwtAndLoadUser } from '../middleware/auth';
 import { User } from '../types';
 import { DEMO_EMAIL_PRIMARY, isDemoEmail } from './demo';
@@ -527,7 +528,7 @@ export function deleteAccount(userId: number, userEmail: string, userRole: strin
       return { error: 'Cannot delete the last admin account', status: 400 };
     }
   }
-  db.prepare('DELETE FROM users WHERE id = ?').run(userId);
+  deleteUserCompletely(userId);
   return { success: true };
 }
 

server/src/services/userCleanupService.ts

@@ -0,0 +1,21 @@
+import { db } from '../db/database';
+
+function cleanupUserReferences(userId: number): void {
+  db.prepare('UPDATE trip_members SET invited_by = NULL WHERE invited_by = ?').run(userId);
+  db.prepare('UPDATE budget_items SET paid_by_user_id = NULL WHERE paid_by_user_id = ?').run(userId);
+  db.prepare('DELETE FROM share_tokens WHERE created_by = ?').run(userId);
+  db.prepare('DELETE FROM journey_share_tokens WHERE created_by = ?').run(userId);
+  // Owned journeys cascade-delete their entries/contributors/share_tokens/photos via journey_id FKs
+  db.prepare('DELETE FROM journeys WHERE user_id = ?').run(userId);
+  // Entries authored on other users' journeys (not covered by the cascade above)
+  db.prepare('DELETE FROM journey_entries WHERE author_id = ?').run(userId);
+  db.prepare('DELETE FROM journey_contributors WHERE user_id = ?').run(userId);
+}
+
+export function deleteUserCompletely(userId: number): void {
+  const tx = db.transaction((id: number) => {
+    cleanupUserReferences(id);
+    db.prepare('DELETE FROM users WHERE id = ?').run(id);
+  });
+  tx(userId);
+}