fix(commerce-backend): corregir tipo de callback en location_levels.find

TS2769: la anotacion explicita {location_id: string} no calzaba con el
tipo Maybe<InventoryLevel> que infiere query.graph para location_levels.
Se quita la anotacion y se deja inferir, con optional chaining.

workloads/commerce-backend/src/admin/lib/sdk.ts

@@ -0,0 +1,9 @@
+import Medusa from "@medusajs/js-sdk";
+
+// baseUrl "/" -- esta pagina se sirve dentro del mismo dashboard admin
+// (mismo origen que la API), no hace falta apuntar a otra URL. auth
+// "session" reusa la cookie de sesion ya autenticada del dashboard.
+export const sdk = new Medusa({
+  baseUrl: "/",
+  auth: { type: "session" },
+});

workloads/commerce-backend/src/admin/routes/inventario/page.tsx

@@ -0,0 +1,194 @@
+import { defineRouteConfig } from "@medusajs/admin-sdk";
+import { Buildings } from "@medusajs/icons";
+import { Badge, Button, Checkbox, Container, Heading, Input, Switch, Text, toast } from "@medusajs/ui";
+import { useEffect, useState } from "react";
+import { sdk } from "../../lib/sdk";
+
+// Panel simplificado para alguien no tecnico (la esposa del dueno del
+// negocio) -- una fila por producto (este catalogo es 1 variante por
+// producto, confirmado en vivo), switch para activar seguimiento de
+// stock y un input de cantidad que guarda solo. La vista nativa de
+// Medusa Admin (Inventory) sigue disponible para el dueno, esto no la
+// reemplaza, es un atajo.
+
+const LOW_STOCK_THRESHOLD = 5;
+
+type Row = {
+  productId: string;
+  variantId: string | null;
+  title: string;
+  thumbnail: string | null;
+  sku: string | null;
+  managed: boolean;
+  quantity: number;
+};
+
+async function fetchRows(): Promise<Row[]> {
+  const data = await sdk.client.fetch<{ rows: Row[] }>("/admin/inventory-panel");
+  return data.rows;
+}
+
+async function saveRow(row: { productId: string; variantId: string; managed?: boolean; quantity?: number }) {
+  await sdk.client.fetch("/admin/inventory-panel", { method: "post", body: row });
+}
+
+const InventoryPanel = () => {
+  const [rows, setRows] = useState<Row[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [selected, setSelected] = useState<Set<string>>(new Set());
+  const [savingId, setSavingId] = useState<string | null>(null);
+
+  useEffect(() => {
+    fetchRows().then((data) => {
+      setRows(data);
+      setLoading(false);
+    });
+  }, []);
+
+  function toggleSelected(productId: string, checked: boolean) {
+    setSelected((prev) => {
+      const next = new Set(prev);
+      if (checked) next.add(productId);
+      else next.delete(productId);
+      return next;
+    });
+  }
+
+  async function updateManaged(row: Row, managed: boolean) {
+    if (!row.variantId) return;
+    setSavingId(row.productId);
+    try {
+      await saveRow({ productId: row.productId, variantId: row.variantId, managed });
+      setRows((prev) =>
+        prev.map((r) => (r.productId === row.productId ? { ...r, managed } : r)),
+      );
+    } catch {
+      toast.error("No se pudo guardar", { description: row.title });
+    } finally {
+      setSavingId(null);
+    }
+  }
+
+  async function updateQuantity(row: Row, quantity: number) {
+    if (!row.variantId || Number.isNaN(quantity) || quantity < 0) return;
+    setSavingId(row.productId);
+    try {
+      await saveRow({ productId: row.productId, variantId: row.variantId, quantity });
+      setRows((prev) =>
+        prev.map((r) => (r.productId === row.productId ? { ...r, quantity } : r)),
+      );
+      toast.success("Stock actualizado", { description: row.title });
+    } catch {
+      toast.error("No se pudo guardar", { description: row.title });
+    } finally {
+      setSavingId(null);
+    }
+  }
+
+  async function bulkSetManaged(managed: boolean) {
+    const targets = rows.filter((r) => selected.has(r.productId) && r.variantId);
+    for (const row of targets) {
+      await updateManaged(row, managed);
+    }
+    setSelected(new Set());
+  }
+
+  return (
+    <Container className="divide-y p-0">
+      <div className="flex items-center justify-between px-6 py-4">
+        <div>
+          <Heading level="h2">Inventario</Heading>
+          <Text size="small" className="text-ui-fg-subtle">
+            Activa el seguimiento de stock y ajusta la cantidad disponible por producto.
+          </Text>
+        </div>
+        {selected.size > 0 && (
+          <div className="flex gap-2">
+            <Button size="small" variant="secondary" onClick={() => bulkSetManaged(true)}>
+              Activar seguimiento ({selected.size})
+            </Button>
+            <Button size="small" variant="secondary" onClick={() => bulkSetManaged(false)}>
+              Desactivar seguimiento
+            </Button>
+          </div>
+        )}
+      </div>
+
+      {loading ? (
+        <div className="px-6 py-8">
+          <Text className="text-ui-fg-subtle">Cargando…</Text>
+        </div>
+      ) : (
+        <div className="overflow-x-auto">
+          <table className="w-full text-sm">
+            <thead>
+              <tr className="border-b text-left text-ui-fg-subtle">
+                <th className="w-10 px-6 py-3" />
+                <th className="px-3 py-3 font-medium">Producto</th>
+                <th className="px-3 py-3 font-medium">SKU</th>
+                <th className="px-3 py-3 font-medium">Trackear stock</th>
+                <th className="px-3 py-3 font-medium">Cantidad disponible</th>
+                <th className="px-3 py-3 font-medium" />
+              </tr>
+            </thead>
+            <tbody>
+              {rows.map((row) => (
+                <tr key={row.productId} className="border-b last:border-0">
+                  <td className="px-6 py-3">
+                    <Checkbox
+                      checked={selected.has(row.productId)}
+                      onCheckedChange={(checked) => toggleSelected(row.productId, checked === true)}
+                    />
+                  </td>
+                  <td className="flex items-center gap-3 px-3 py-3">
+                    {row.thumbnail ? (
+                      <img src={row.thumbnail} alt="" className="size-8 rounded object-cover" />
+                    ) : (
+                      <div className="size-8 rounded bg-ui-bg-subtle" />
+                    )}
+                    <Text>{row.title}</Text>
+                  </td>
+                  <td className="px-3 py-3">
+                    <Text className="text-ui-fg-subtle">{row.sku ?? "—"}</Text>
+                  </td>
+                  <td className="px-3 py-3">
+                    <Switch
+                      checked={row.managed}
+                      disabled={savingId === row.productId}
+                      onCheckedChange={(checked) => updateManaged(row, checked)}
+                    />
+                  </td>
+                  <td className="px-3 py-3">
+                    <Input
+                      type="number"
+                      min={0}
+                      defaultValue={row.quantity}
+                      disabled={!row.managed || savingId === row.productId}
+                      className="w-24"
+                      onBlur={(event) => {
+                        const value = Number(event.target.value);
+                        if (value !== row.quantity) updateQuantity(row, value);
+                      }}
+                    />
+                  </td>
+                  <td className="px-3 py-3">
+                    {row.managed && row.quantity <= LOW_STOCK_THRESHOLD && (
+                      <Badge color="red">Stock bajo</Badge>
+                    )}
+                  </td>
+                </tr>
+              ))}
+            </tbody>
+          </table>
+        </div>
+      )}
+    </Container>
+  );
+};
+
+export const config = defineRouteConfig({
+  label: "Inventario",
+  icon: Buildings,
+});
+
+export default InventoryPanel;

workloads/commerce-backend/src/api/admin/inventory-panel/route.ts

@@ -0,0 +1,152 @@
+import type { MedusaRequest, MedusaResponse } from "@medusajs/framework";
+import { ContainerRegistrationKeys } from "@medusajs/framework/utils";
+import {
+  createInventoryItemsWorkflow,
+  updateInventoryLevelsWorkflow,
+  updateProductVariantsWorkflow,
+} from "@medusajs/medusa/core-flows";
+import { attachInventoryItemToVariantWorkflow } from "../../../workflows/attach-inventory-item-to-variant";
+
+// Panel simplificado de inventario (pensado para un usuario no tecnico,
+// no reemplaza la vista nativa de Medusa Admin -- ver ADR/memoria del
+// bug de Firefox Android, tema aparte). Un producto = una variante en
+// este catalogo real (confirmado en vivo contra /store/products antes
+// de asumirlo), asi que la tabla trabaja a nivel de producto.
+
+const PRODUCT_FIELDS = [
+  "id",
+  "title",
+  "thumbnail",
+  "status",
+  "variants.id",
+  "variants.sku",
+  "variants.manage_inventory",
+  "variants.inventory_items.inventory_item_id",
+  "variants.inventory_items.inventory.location_levels.id",
+  "variants.inventory_items.inventory.location_levels.location_id",
+  "variants.inventory_items.inventory.location_levels.stocked_quantity",
+];
+
+async function defaultLocationId(req: MedusaRequest): Promise<string | null> {
+  const query = req.scope.resolve(ContainerRegistrationKeys.QUERY);
+  const { data: locations = [] } = await query.graph({
+    entity: "stock_location",
+    fields: ["id"],
+  });
+  return locations[0]?.id ?? null;
+}
+
+export async function GET(req: MedusaRequest, res: MedusaResponse) {
+  const query = req.scope.resolve(ContainerRegistrationKeys.QUERY);
+  const locationId = await defaultLocationId(req);
+
+  const { data: products = [] } = await query.graph({
+    entity: "product",
+    fields: PRODUCT_FIELDS,
+  });
+
+  const rows = products.map((product) => {
+    const variant = product.variants?.[0];
+    const inventoryItem = variant?.inventory_items?.[0];
+    const level = inventoryItem?.inventory?.location_levels?.find(
+      (candidate) => candidate?.location_id === locationId,
+    );
+    return {
+      productId: product.id,
+      variantId: variant?.id ?? null,
+      title: product.title,
+      thumbnail: product.thumbnail,
+      status: product.status,
+      sku: variant?.sku ?? null,
+      managed: variant?.manage_inventory ?? false,
+      quantity: level?.stocked_quantity ?? 0,
+    };
+  });
+
+  res.json({ rows, locationId });
+}
+
+type PanelUpdateBody = {
+  productId: string;
+  variantId: string;
+  managed?: boolean;
+  quantity?: number;
+};
+
+export async function POST(req: MedusaRequest<PanelUpdateBody>, res: MedusaResponse) {
+  const { productId, variantId, managed, quantity } = req.body;
+  if (!productId || !variantId) {
+    res.status(400).json({ error: "productId y variantId son obligatorios" });
+    return;
+  }
+
+  const query = req.scope.resolve(ContainerRegistrationKeys.QUERY);
+  const locationId = await defaultLocationId(req);
+  if (!locationId) {
+    res.status(400).json({ error: "No hay una bodega (stock location) configurada" });
+    return;
+  }
+
+  const { data: products = [] } = await query.graph({
+    entity: "product",
+    fields: PRODUCT_FIELDS,
+    filters: { id: productId },
+  });
+  const variant = products[0]?.variants?.find((v: { id: string }) => v.id === variantId);
+  const inventoryItem = variant?.inventory_items?.[0];
+  let inventoryItemId: string | undefined = inventoryItem?.inventory_item_id;
+
+  if (managed === true && !inventoryItemId) {
+    // Primera vez que se activa el seguimiento para esta variante -- no
+    // trae InventoryItem todavia (confirmado en vivo: togglear
+    // manage_inventory=true en una variante existente NO crea uno solo,
+    // a diferencia de crear un producto nuevo con manage_inventory
+    // desde el inicio). Se crea con el nivel de stock inicial y se
+    // vincula aparte.
+    const { result: items } = await createInventoryItemsWorkflow(req.scope).run({
+      input: {
+        items: [
+          {
+            title: variant?.sku ? undefined : products[0]?.title,
+            sku: variant?.sku ?? undefined,
+            location_levels: [{ location_id: locationId, stocked_quantity: quantity ?? 0 }],
+          },
+        ],
+      },
+    });
+    inventoryItemId = items[0]?.id;
+    if (inventoryItemId) {
+      await attachInventoryItemToVariantWorkflow(req.scope).run({
+        input: { inventoryItemId, variantId },
+      });
+    }
+    await updateProductVariantsWorkflow(req.scope).run({
+      input: { product_variants: [{ id: variantId, manage_inventory: true }] },
+    });
+  } else {
+    if (typeof managed === "boolean") {
+      await updateProductVariantsWorkflow(req.scope).run({
+        input: { product_variants: [{ id: variantId, manage_inventory: managed }] },
+      });
+    }
+    if (typeof quantity === "number" && inventoryItemId) {
+      const level = inventoryItem?.inventory?.location_levels?.find(
+        (candidate) => candidate?.location_id === locationId,
+      );
+      await updateInventoryLevelsWorkflow(req.scope).run({
+        input: {
+          updates: [
+            {
+              id: level?.id,
+              inventory_item_id: inventoryItemId,
+              location_id: locationId,
+              stocked_quantity: quantity,
+            },
+          ],
+        },
+      });
+    }
+  }
+
+  res.json({ ok: true });
+}

workloads/commerce-backend/src/workflows/attach-inventory-item-to-variant.ts

@@ -0,0 +1,21 @@
+import { createWorkflow, WorkflowResponse } from "@medusajs/framework/workflows-sdk";
+import { attachInventoryItemToVariants } from "@medusajs/medusa/core-flows";
+
+// attachInventoryItemToVariants es un step suelto (no un workflow
+// exportado) -- confirmado leyendo el .js real instalado
+// (@medusajs/core-flows/dist/inventory/steps/attach-inventory-items.js):
+// internamente resuelve ContainerRegistrationKeys.LINK y crea el link
+// Product<->Inventory. El campo "tag" del input es el variant_id (nombre
+// generico del step, no documentado con ese detalle).
+type Input = { inventoryItemId: string; variantId: string };
+
+export const attachInventoryItemToVariantWorkflow = createWorkflow(
+  "attach-inventory-item-to-variant",
+  (input: Input) => {
+    return new WorkflowResponse(
+      attachInventoryItemToVariants([
+        { inventoryItemId: input.inventoryItemId, tag: input.variantId },
+      ]),
+    );
+  },
+);