fix: real checkout-datetime version/capability fix + payment-customization schema

checkout-datetime (re-enabled, no longer excluded):
- api_version was declared as "2025-10" but @shopify/ui-extensions-react
  has no release for that channel at all (jumps 2025.7.4 -> 2026.0.0
  directly) — downgraded to "2025-07" to match what's actually installed
  and what the code was written/typed against. Verified all three targets
  (purchase.checkout.block.render, purchase.thank-you.block.render,
  customer-account.order-status.block.render) exist in that package
  version before making the change.
- [extensions.capabilities] network_access was missing entirely (dropped
  during the multi-pin-pickup rewrite) despite Checkout.jsx's authedFetch()
  genuinely needing it — the checkout sandbox would have silently blocked
  every fetch() call at runtime even though it deployed fine.
- OrderStatus.jsx imported reactExtension/BlockStack/Heading/Text/
  useTranslate from the *checkout* surface behind a "might not be in the
  type definition" @ts-ignore, for a *customer-account* target. Verified
  @shopify/ui-extensions-react/customer-account re-exports the same
  component names for real and switched the import, removing the
  @ts-ignore entirely — it now typechecks for real instead of being
  suppressed.
- lib.js's shared useConfirmationText() hardcoded useTranslate/
  useAttributes from the checkout surface, but was called from both
  ThankYou.jsx (checkout) and OrderStatus.jsx (customer-account) — hooks
  are bound to their surface's React context, so calling checkout-bound
  hooks from a customer-account extension would break at runtime even
  though nothing caught it statically. Changed it to a plain function
  (confirmationText) taking translate/attributes as parameters; each
  caller now calls its own surface's hooks and passes the results in.

payment-customization: schema.graphql never existed (not gitignored,
just never fetched/committed when this extension was added — HANDOVER.md's
note that this was "by design" was wrong). Fetched via
`shopify app function schema` and committed, matching the pattern already
used by validation-slot/delivery-customization.

Together these three issues were silently failing every single
`shopify app deploy` for the whole app, which is why shopify.app.toml's
App Proxy URL fix never actually reached Shopify's servers.

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

extensions/checkout-datetime/shopify.extension.toml

@@ -1,4 +1,4 @@
-api_version = "2025-10"
+api_version = "2025-07"
 
 [[extensions]]
 type = "ui_extension"
@@ -33,3 +33,10 @@ target = "purchase.thank-you.block.render"
 [[extensions.targeting]]
 module = "./src/OrderStatus.jsx"
 target = "customer-account.order-status.block.render"
+
+# Required — Checkout.jsx's authedFetch() calls this app's own backend
+# (checkout.scheduling.* routes). Was present in the extension's original
+# toml but missing after the multi-pin-pickup rewrite, which would have
+# had the checkout sandbox silently block every fetch() call at runtime.
+[extensions.capabilities]
+network_access = true

extensions/checkout-datetime/src/OrderStatus.jsx

@@ -1,13 +1,12 @@
-import { reactExtension, BlockStack, Heading, Text } from "@shopify/ui-extensions-react/checkout";
-import { useConfirmationText } from "./lib.js";
-import { useTranslate } from "@shopify/ui-extensions-react/checkout";
+import { reactExtension, BlockStack, Heading, Text, useTranslate, useAttributes } from "@shopify/ui-extensions-react/customer-account";
+import { confirmationText } from "./lib.js";
 
-// @ts-ignore - customer account targets might not be in the checkout UI extensions type definition
 export default reactExtension("customer-account.order-status.block.render", () => <Extension />);
 
 function Extension() {
-  const text = useConfirmationText();
   const translate = useTranslate();
+  const attributes = useAttributes();
+  const text = confirmationText(translate, attributes);
   if (!text) return null;
   return (
     <BlockStack spacing="base">

extensions/checkout-datetime/src/ThankYou.jsx

@@ -1,12 +1,12 @@
-import { reactExtension, BlockStack, Heading, Text } from "@shopify/ui-extensions-react/checkout";
-import { useConfirmationText } from "./lib.js";
-import { useTranslate } from "@shopify/ui-extensions-react/checkout";
+import { reactExtension, BlockStack, Heading, Text, useTranslate, useAttributes } from "@shopify/ui-extensions-react/checkout";
+import { confirmationText } from "./lib.js";
 
 export default reactExtension("purchase.thank-you.block.render", () => <Extension />);
 
 function Extension() {
-  const text = useConfirmationText();
   const translate = useTranslate();
+  const attributes = useAttributes();
+  const text = confirmationText(translate, attributes);
   if (!text) return null;
   return (
     <BlockStack spacing="base">

extensions/checkout-datetime/src/lib.js

@@ -1,5 +1,3 @@
-import { useTranslate, useAttributes } from "@shopify/ui-extensions-react/checkout";
-
 export const METHODS = [
   { value: "PICKUP", labelKey: "method_pickup", attrLabel: "Pickup date" },
   { value: "LOCAL_DELIVERY", labelKey: "method_local_delivery", attrLabel: "Delivery date" },
@@ -57,10 +55,16 @@ const CONFIRMATION_LABEL = {
   SHIPPING: "confirmation_shipping",
 };
 
-export function useConfirmationText() {
-  const translate = useTranslate();
-  const attributes = useAttributes();
-  
+// Plain function, not a hook — useTranslate()/useAttributes() are bound to
+// whichever extension surface calls them (checkout vs. customer-account),
+// so ThankYou.jsx and OrderStatus.jsx each call their own surface's hooks
+// and pass the results in here, rather than this shared file importing
+// hooks pinned to one surface and being called from the other.
+/**
+ * @param {(key: string) => string} translate
+ * @param {Array<{key: string, value: string}> | undefined} attributes
+ */
+export function confirmationText(translate, attributes) {
   const method = readAttribute(attributes, "dd_method");
   const date = readAttribute(attributes, "dd_date");
   const startMin = readAttribute(attributes, "dd_start_min");