fix(medications): give backdated/manual intakes the same Undo the card has

Logging a dose via Medications → Add → "Log intake" (incl. backdated)
or the dashboard's medication-intake quick-add toasted success with no
Undo, unlike the card's own take/skip path — a dose logged against the
wrong medication (easy on the quick-add, which auto-picks) was only
correctable via detail page → history → find row → delete. Both paths
now capture the created event id and attach the same Undo action.

src/components/dashboard/medication-intake-quick-add.tsx

@@ -30,6 +30,7 @@ import {
 } from "@/lib/medications/window-status";
 import { useAuth } from "@/hooks/use-auth";
 import { ApiError, apiGet, apiPost } from "@/lib/api/api-fetch";
+import { runUndoIntake } from "@/components/medications/use-medication-intake";
 
 /**
  * v1.4.37 W7b — dashboard "Hinzufügen" → "Medikamenteneinnahme" quick-add.
@@ -271,11 +272,18 @@ export function MedicationIntakeQuickAdd({
       const doseDeviates =
         trimmedDose.length > 0 &&
         trimmedDose !== (selectedMedication?.dose ?? "").trim();
-      await apiPost(`/api/medications/${medicationId}/intake`, {
-        takenAt: timestamp,
-        skipped: false,
-        ...(doseDeviates && { doseTaken: trimmedDose }),
-      });
+      // v1.30.1 M7 — the route returns the created event
+      // (`apiSuccess(event, 201)`), same shape the card's take/skip path
+      // already reads; the id drives the new Undo action below.
+      const created = await apiPost<{ id?: string } | undefined>(
+        `/api/medications/${medicationId}/intake`,
+        {
+          takenAt: timestamp,
+          skipped: false,
+          ...(doseDeviates && { doseTaken: trimmedDose }),
+        },
+      );
+      const eventId = created?.id;
 
       await invalidateKeys(queryClient, medicationDependentKeys);
       // Fan-out to every inline compliance chart key (one per medication)
@@ -284,7 +292,26 @@ export function MedicationIntakeQuickAdd({
         queryKey: queryKeys.complianceChartInline(),
       });
 
-      toast.success(t("common.saved"));
+      toast.success(
+        t("common.saved"),
+        eventId && selectedMedication
+          ? {
+              action: {
+                label: t("medications.intakeUndo"),
+                onClick: () =>
+                  void runUndoIntake({
+                    medication: {
+                      id: medicationId,
+                      name: selectedMedication.name,
+                    },
+                    eventId,
+                    t,
+                    queryClient,
+                  }),
+              },
+            }
+          : undefined,
+      );
       onSuccess?.();
     } catch (err) {
       setError(

src/components/medications/log-intake-dialog.tsx

@@ -33,7 +33,10 @@ import { NativeSelect } from "@/components/ui/native-select";
 import { Switch } from "@/components/ui/switch";
 import { useTranslations } from "@/lib/i18n/context";
 import { formatDose } from "@/lib/medications/format-dose";
-import { runLogIntake } from "@/components/medications/use-medication-intake";
+import {
+  runLogIntake,
+  runUndoIntake,
+} from "@/components/medications/use-medication-intake";
 
 interface LogIntakeSchedule {
   windowStart: string;
@@ -194,6 +197,15 @@ export function LogIntakeDialog({
         ...(doseDeviates && { doseTaken: trimmedDose }),
         t,
         queryClient,
+        // v1.30.1 M7 — a backdated/manual intake now gets the same
+        // Undo affordance the card's take/skip path already has.
+        undoIntake: (eventId) =>
+          runUndoIntake({
+            medication: { id: med.id, name: med.name },
+            eventId,
+            t,
+            queryClient,
+          }),
       });
       if (ok) onOpenChange(false);
     } finally {

src/components/medications/use-medication-intake.ts

@@ -215,6 +215,12 @@ export async function runLogIntake(deps: {
   doseTaken?: string;
   t: Translator;
   queryClient: QueryClient;
+  /**
+   * v1.30.1 M7 — reverse the just-logged intake. Optional so existing
+   * unit tests that don't care about Undo can omit it; the toast simply
+   * carries no action when it's absent.
+   */
+  undoIntake?: (eventId: string) => void | Promise<void>;
 }): Promise<boolean> {
   const {
     medication,
@@ -224,22 +230,42 @@ export async function runLogIntake(deps: {
     doseTaken,
     t,
     queryClient,
+    undoIntake,
   } = deps;
   try {
     const body: Record<string, unknown> = { skipped };
     if (!skipped) body.takenAt = takenAt;
     if (scheduledFor) body.scheduledFor = scheduledFor;
     if (!skipped && doseTaken) body.doseTaken = doseTaken;
-    await apiPost(`/api/medications/${medication.id}/intake`, body);
-    await invalidateMedicationReads(queryClient);
-    toast.success(
-      t(
-        skipped
-          ? "medications.intakeToastSkipped"
-          : "medications.intakeToastTaken",
-        { name: medication.name },
-      ),
+    // v1.30.1 M7 — the route returns the created event
+    // (`apiSuccess(event, 201)`, same as the card's `runRecordIntake`);
+    // its id drives the Undo action below.
+    const created = await apiPost<{ id?: string } | undefined>(
+      `/api/medications/${medication.id}/intake`,
+      body,
     );
+    const eventId = created?.id;
+    await invalidateMedicationReads(queryClient);
+    const message = t(
+      skipped
+        ? "medications.intakeToastSkipped"
+        : "medications.intakeToastTaken",
+      { name: medication.name },
+    );
+    // v1.30.1 M7 — only pass a second `toast.success` argument when there's
+    // a real Undo action to attach; keeps the no-undo call signature
+    // identical to the pre-fix behaviour (existing unit tests assert the
+    // single-argument call).
+    if (eventId && undoIntake) {
+      toast.success(message, {
+        action: {
+          label: t("medications.intakeUndo"),
+          onClick: () => void undoIntake(eventId),
+        },
+      });
+    } else {
+      toast.success(message);
+    }
     return true;
   } catch {
     toast.error(t("medications.intakeToastFailed", { name: medication.name }));