feat: warn against harvesting honey during a treatment's Wartezeit

Treatments (Ameisensäure, Oxalsäure, etc.) can require a legally
mandated withdrawal period before honey from that colony may be sold.
Nothing in the app tracked this before, so a beekeeper had no
safeguard against harvesting into an active withdrawal window.

Treatments now optionally record withdrawalPeriodDays (from the
product's Packungsbeilage). The new harvest form fetches each
candidate colony's active withdrawal window and shows an inline
warning naming the product and the date it clears, computed as
max(endDate ?? date) + withdrawalPeriodDays across a colony's
treatments, restricted to windows still in the future.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

ApiCore-Frontend/src/app/(app)/colonies/[id]/colony-treatments.tsx

@@ -49,6 +49,9 @@ export function ColonyTreatmentsCard({ colonyId }: { colonyId: string }) {
               {treatment.method ? ` · ${treatment.method}` : ""}
             </p>
             {treatment.reason ? <p>Grund: {treatment.reason}</p> : null}
+            {treatment.withdrawalPeriodDays !== null ? (
+              <p>Wartezeit: {treatment.withdrawalPeriodDays} Tag(e)</p>
+            ) : null}
           </div>
         ))}
       </CardContent>

ApiCore-Frontend/src/app/(app)/colonies/[id]/treatment-edit-dialog.tsx

@@ -26,6 +26,9 @@ export function TreatmentEditDialog({ treatment }: { treatment: Treatment }) {
   const [method, setMethod] = useState(treatment.method ?? "");
   const [reason, setReason] = useState(treatment.reason ?? "");
   const [notes, setNotes] = useState(treatment.notes ?? "");
+  const [withdrawalPeriodDays, setWithdrawalPeriodDays] = useState(
+    treatment.withdrawalPeriodDays?.toString() ?? "",
+  );
 
   const mutation = useMutation({
     mutationFn: () =>
@@ -36,6 +39,7 @@ export function TreatmentEditDialog({ treatment }: { treatment: Treatment }) {
         method: method || undefined,
         reason: reason || undefined,
         notes: notes || undefined,
+        withdrawalPeriodDays: withdrawalPeriodDays ? Number(withdrawalPeriodDays) : undefined,
       }),
     onSuccess: () => {
       void queryClient.invalidateQueries({
@@ -107,6 +111,17 @@ export function TreatmentEditDialog({ treatment }: { treatment: Treatment }) {
               onChange={(event) => setReason(event.target.value)}
             />
           </div>
+          <div className="flex flex-col gap-2">
+            <Label htmlFor="treatment-edit-withdrawal">Wartezeit (Tage)</Label>
+            <Input
+              id="treatment-edit-withdrawal"
+              type="number"
+              inputMode="numeric"
+              min={0}
+              value={withdrawalPeriodDays}
+              onChange={(event) => setWithdrawalPeriodDays(event.target.value)}
+            />
+          </div>
           <div className="flex flex-col gap-2">
             <Label htmlFor="treatment-edit-notes">Notizen</Label>
             <Textarea

ApiCore-Frontend/src/app/(app)/harvests/new/page.tsx

@@ -4,10 +4,11 @@ import { FormEvent, useState } from "react";
 import { useRouter, useSearchParams } from "next/navigation";
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import { toast } from "sonner";
-import { Boxes } from "lucide-react";
+import { Boxes, AlertTriangle } from "lucide-react";
 import { fetchApiaries } from "@/lib/apiaries/api";
 import { fetchColonies } from "@/lib/colonies/api";
 import { createHarvest } from "@/lib/harvests/api";
+import { fetchWithdrawalStatus } from "@/lib/treatments/api";
 import { ApiError } from "@/lib/auth/api-client";
 import { queueHarvest } from "@/lib/offline/db";
 import { Button } from "@/components/ui/button";
@@ -47,6 +48,15 @@ export default function NewHarvestPage() {
   const apiaryColonies = (colonies ?? []).filter(
     (colony) => colony.apiaryId === apiaryId && colony.status === "ACTIVE",
   );
+  const apiaryColonyIds = apiaryColonies.map((colony) => colony.id);
+  const { data: withdrawalStatuses } = useQuery({
+    queryKey: ["treatments", "withdrawal-status", apiaryColonyIds],
+    queryFn: () => fetchWithdrawalStatus(apiaryColonyIds),
+    enabled: apiaryColonyIds.length > 0,
+  });
+  const withdrawalByColony = new Map(
+    (withdrawalStatuses ?? []).map((status) => [status.colonyId, status]),
+  );
 
   const mutation = useMutation({
     mutationFn: createHarvest,
@@ -144,22 +154,33 @@ export default function NewHarvestPage() {
                 </p>
               ) : null}
               <div className="flex flex-col gap-2">
-                {apiaryColonies.map((colony) => (
-                  <label
-                    key={colony.id}
-                    className="flex h-11 items-center gap-3 text-sm"
-                    htmlFor={`harvest-colony-${colony.id}`}
-                  >
-                    <input
-                      id={`harvest-colony-${colony.id}`}
-                      type="checkbox"
-                      className="size-5"
-                      checked={colonyIds.includes(colony.id)}
-                      onChange={(event) => toggleColony(colony.id, event.target.checked)}
-                    />
-                    {colony.code}
-                  </label>
-                ))}
+                {apiaryColonies.map((colony) => {
+                  const withdrawal = withdrawalByColony.get(colony.id);
+                  return (
+                    <div key={colony.id} className="flex flex-col gap-1">
+                      <label
+                        className="flex h-11 items-center gap-3 text-sm"
+                        htmlFor={`harvest-colony-${colony.id}`}
+                      >
+                        <input
+                          id={`harvest-colony-${colony.id}`}
+                          type="checkbox"
+                          className="size-5"
+                          checked={colonyIds.includes(colony.id)}
+                          onChange={(event) => toggleColony(colony.id, event.target.checked)}
+                        />
+                        {colony.code}
+                      </label>
+                      {withdrawal ? (
+                        <p className="flex items-center gap-1.5 pl-8 text-xs text-destructive">
+                          <AlertTriangle className="size-3.5 shrink-0" />
+                          Wartezeit ({withdrawal.product}) bis{" "}
+                          {new Date(withdrawal.activeUntil).toLocaleDateString("de-DE")}
+                        </p>
+                      ) : null}
+                    </div>
+                  );
+                })}
               </div>
             </div>
             <div className="flex flex-col gap-2">

ApiCore-Frontend/src/app/(app)/treatments/new/page.tsx

@@ -45,6 +45,7 @@ export default function NewTreatmentPage() {
   const [method, setMethod] = useState("");
   const [reason, setReason] = useState("");
   const [notes, setNotes] = useState("");
+  const [withdrawalPeriodDays, setWithdrawalPeriodDays] = useState("");
   const [error, setError] = useState<string | null>(null);
 
   const mutation = useMutation({
@@ -83,6 +84,7 @@ export default function NewTreatmentPage() {
       method: method || undefined,
       reason: reason || undefined,
       notes: notes || undefined,
+      withdrawalPeriodDays: withdrawalPeriodDays ? Number(withdrawalPeriodDays) : undefined,
     });
   }
 
@@ -160,6 +162,22 @@ export default function NewTreatmentPage() {
                 onChange={(event) => setReason(event.target.value)}
               />
             </div>
+            <div className="flex flex-col gap-2">
+              <Label htmlFor="treatment-withdrawal">Wartezeit (Tage)</Label>
+              <Input
+                id="treatment-withdrawal"
+                type="number"
+                inputMode="numeric"
+                min={0}
+                className="h-11"
+                value={withdrawalPeriodDays}
+                onChange={(event) => setWithdrawalPeriodDays(event.target.value)}
+              />
+              <p className="text-xs text-muted-foreground">
+                Laut Packungsbeilage des Mittels – solange darf aus diesem Volk kein Honig
+                geerntet werden.
+              </p>
+            </div>
             <div className="flex flex-col gap-2">
               <Label htmlFor="treatment-notes">Notizen</Label>
               <Textarea

ApiCore-Frontend/src/lib/treatments/api.ts

@@ -1,10 +1,26 @@
 import { apiFetch } from "@/lib/auth/api-client";
-import { CreateTreatmentInput, Treatment, UpdateTreatmentInput } from "./types";
+import {
+  CreateTreatmentInput,
+  Treatment,
+  UpdateTreatmentInput,
+  WithdrawalStatus,
+} from "./types";
 
 export function fetchColonyTreatments(colonyId: string): Promise<Treatment[]> {
   return apiFetch<Treatment[]>(`/colonies/${colonyId}/treatments`);
 }
 
+export function fetchWithdrawalStatus(
+  colonyIds: string[],
+): Promise<WithdrawalStatus[]> {
+  if (colonyIds.length === 0) {
+    return Promise.resolve([]);
+  }
+  return apiFetch<WithdrawalStatus[]>(
+    `/treatments/withdrawal-status?colonyIds=${colonyIds.join(",")}`,
+  );
+}
+
 export function createTreatment(input: CreateTreatmentInput): Promise<Treatment> {
   return apiFetch<Treatment>("/treatments", {
     method: "POST",

ApiCore-Frontend/src/lib/treatments/types.ts

@@ -12,6 +12,7 @@ export interface Treatment {
   reason: string | null;
   batchNumber: string | null;
   notes: string | null;
+  withdrawalPeriodDays: number | null;
   createdAt: string;
 }
 
@@ -27,6 +28,7 @@ export interface CreateTreatmentInput {
   reason?: string;
   batchNumber?: string;
   notes?: string;
+  withdrawalPeriodDays?: number;
 }
 
 export interface UpdateTreatmentInput {
@@ -40,4 +42,11 @@ export interface UpdateTreatmentInput {
   reason?: string;
   batchNumber?: string;
   notes?: string;
+  withdrawalPeriodDays?: number;
+}
+
+export interface WithdrawalStatus {
+  colonyId: string;
+  activeUntil: string;
+  product: string;
 }