Merge branch 'worktree-agent-a02f88e8490625846'

# Conflicts:
#	GerbilManagerWebAPI/ApplicationContext.cs
#	GerbilManagerWebAPI/Program.cs
#	gerbil-manager-web/e2e/mock-data.ts
#	gerbil-manager-web/src/App.tsx
#	gerbil-manager-web/src/components/AppShell.tsx
#	gerbil-manager-web/src/strings/de.ts

gerbil-manager-web/e2e/mock-data.ts

@@ -91,6 +91,8 @@ export interface MockDb {
   reservations: Record<string, unknown>[]
   // WAITLIST: Warteliste/Nachfrage (RennmausPro nachfrage_tb)
   waitingList: Record<string, unknown>[]
+  // RÜCKNAHMEN: zurückgenommene Tiere (CRUD /returns)
+  returns: Record<string, unknown>[]
 }
 
 function gerbil(
@@ -617,5 +619,6 @@ export function seedDb(): MockDb {
         createdAt: '2026-04-10T00:00:00Z',
       },
     ],
+    returns: [],
   }
 }