feat(backend): guest-facing Wahl result endpoint

GET /api/wahl/guest/results (guest JWT) returns, per Wahl the guest took
part in, their assignment: status PENDING (algorithm not run yet) /
ASSIGNED (workshopName + wunschRang) / UNASSIGNED (no capacity left).
Verified both PENDING and ASSIGNED paths against local Postgres.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

backend/src/wahl/wahl.controller.ts

@@ -78,6 +78,14 @@ export class WahlController {
     return this.wahl.guestOverview(guest.kcId, guest.guestId);
   }
 
+  /// The guest's own assignment result per Wahl they took part in.
+  @Get('guest/results')
+  @UseGuards(AuthGuard('guest'))
+  guestResults(@Req() req: GuestAuthenticatedRequest) {
+    const guest = req.user!;
+    return this.wahl.guestResults(guest.kcId, guest.guestId);
+  }
+
   /// Guests submit their own workshop preferences (guest JWT, not Authentik).
   @Post(':wahlId/teilnehmer')
   @UseGuards(AuthGuard('guest'))

backend/src/wahl/wahl.service.ts

@@ -56,6 +56,42 @@ export class WahlService {
     };
   }
 
+  /// Guest-facing result view: for every Wahl in the guest's KC where they
+  /// took part, their assignment (workshop name + wish rank), or a pending
+  /// marker if the algorithm has not run for them yet.
+  async guestResults(kcId: string, guestAccountId: string) {
+    const teilnahmen = await this.prisma.teilnehmer.findMany({
+      where: { guestAccountId, wahl: { kcId } },
+      orderBy: { wahl: { createdAt: 'asc' } },
+      select: {
+        wahl: { select: { id: true, name: true, datumsSchluessel: true, teil: true } },
+        zuteilung: { select: { workshopId: true, wunschRang: true, isForced: true } },
+      },
+    });
+
+    const workshopIds = teilnahmen
+      .map((t) => t.zuteilung?.workshopId)
+      .filter((id): id is string => !!id);
+    const workshops = workshopIds.length
+      ? await this.prisma.workshop.findMany({
+          where: { id: { in: workshopIds } },
+          select: { id: true, name: true },
+        })
+      : [];
+    const nameById = new Map(workshops.map((w) => [w.id, w.name]));
+
+    return teilnahmen.map((t) => {
+      const z = t.zuteilung;
+      return {
+        wahl: t.wahl,
+        status: !z ? 'PENDING' : z.workshopId ? 'ASSIGNED' : 'UNASSIGNED',
+        workshopName: z?.workshopId ? (nameById.get(z.workshopId) ?? null) : null,
+        wunschRang: z?.wunschRang ?? null,
+        isForced: z?.isForced ?? false,
+      };
+    });
+  }
+
   async createWorkshop(
     wahlId: string,
     name: string,