feat(shopping): locale-aware grocery links with region settings UI

Shopping links previously hardcoded to US storefronts. Users in other regions
got broken Amazon Fresh and Instacart links. Now locale is stored as a user
setting and passed to GroceryLinkBuilder at request time.

- locale_config.py: per-locale Amazon domain/dept config (already existed)
- grocery_links.py: GroceryLinkBuilder accepts locale=; routes Instacart to .ca
  for Canada, uses amazon_domain per locale, Instacart/Walmart US/CA only
- settings.py: adds 'shopping_locale' to allowed settings keys
- shopping.py: reads locale from user's stored setting on all list/add/update paths
- SettingsView.vue: Shopping Region selector (NA, Europe, APAC, LATAM)
- stores/settings.ts: shoppingLocale reactive state, saves via settings API

app/api/endpoints/settings.py

@@ -10,7 +10,7 @@ from app.db.store import Store
 
 router = APIRouter()
 
-_ALLOWED_KEYS = frozenset({"cooking_equipment", "unit_system"})
+_ALLOWED_KEYS = frozenset({"cooking_equipment", "unit_system", "shopping_locale"})
 
 
 class SettingBody(BaseModel):

app/api/endpoints/shopping.py

@@ -57,12 +57,18 @@ def _in_thread(db_path, fn):
 
 # ── List ──────────────────────────────────────────────────────────────────────
 
+def _locale_from_store(store: Store) -> str:
+    return store.get_setting("shopping_locale") or "us"
+
+
 @router.get("", response_model=list[ShoppingItemResponse])
 async def list_shopping_items(
     include_checked: bool = True,
     session: CloudUser = Depends(get_session),
+    store: Store = Depends(get_store),
 ):
-    builder = GroceryLinkBuilder(tier=session.tier, has_byok=session.has_byok)
+    locale = await asyncio.to_thread(_in_thread, session.db, _locale_from_store)
+    builder = GroceryLinkBuilder(tier=session.tier, has_byok=session.has_byok, locale=locale)
     items = await asyncio.to_thread(
         _in_thread, session.db, lambda s: s.list_shopping_items(include_checked)
     )
@@ -75,8 +81,9 @@ async def list_shopping_items(
 async def add_shopping_item(
     body: ShoppingItemCreate,
     session: CloudUser = Depends(get_session),
+    store: Store = Depends(get_store),
 ):
-    builder = GroceryLinkBuilder(tier=session.tier, has_byok=session.has_byok)
+    builder = GroceryLinkBuilder(tier=session.tier, has_byok=session.has_byok, locale=_locale_from_store(store))
     item = await asyncio.to_thread(
         _in_thread,
         session.db,
@@ -100,6 +107,7 @@ async def add_shopping_item(
 async def add_from_recipe(
     body: BulkAddFromRecipeRequest,
     session: CloudUser = Depends(get_session),
+    store: Store = Depends(get_store),
 ):
     """Add missing ingredients from a recipe to the shopping list.
 
@@ -132,7 +140,7 @@ async def add_from_recipe(
             added.append(item)
         return added
 
-    builder = GroceryLinkBuilder(tier=session.tier, has_byok=session.has_byok)
+    builder = GroceryLinkBuilder(tier=session.tier, has_byok=session.has_byok, locale=_locale_from_store(store))
     items = await asyncio.to_thread(_in_thread, session.db, _run)
     return [_enrich(i, builder) for i in items]
 
@@ -144,8 +152,9 @@ async def update_shopping_item(
     item_id: int,
     body: ShoppingItemUpdate,
     session: CloudUser = Depends(get_session),
+    store: Store = Depends(get_store),
 ):
-    builder = GroceryLinkBuilder(tier=session.tier, has_byok=session.has_byok)
+    builder = GroceryLinkBuilder(tier=session.tier, has_byok=session.has_byok, locale=_locale_from_store(store))
     item = await asyncio.to_thread(
         _in_thread,
         session.db,

app/services/recipe/grocery_links.py

@@ -13,6 +13,7 @@ Walmart is kept inline until cf-core adds Impact network support:
 
 Links are always generated (plain URLs are useful even without affiliate IDs).
 Walmart links only appear when WALMART_AFFILIATE_ID is set.
+Instacart and Walmart are US/CA-only; other locales get Amazon only.
 """
 from __future__ import annotations
 
@@ -23,18 +24,26 @@ from urllib.parse import quote_plus
 from circuitforge_core.affiliates import wrap_url
 
 from app.models.schemas.recipe import GroceryLink
+from app.services.recipe.locale_config import get_locale
 
 logger = logging.getLogger(__name__)
 
 
-def _amazon_fresh_link(ingredient: str) -> GroceryLink:
+def _amazon_link(ingredient: str, locale: str) -> GroceryLink:
+    cfg = get_locale(locale)
     q = quote_plus(ingredient)
-    base = f"https://www.amazon.com/s?k={q}&i=amazonfresh"
-    return GroceryLink(ingredient=ingredient, retailer="Amazon Fresh", url=wrap_url(base, "amazon"))
+    domain = cfg["amazon_domain"]
+    dept = cfg["amazon_grocery_dept"]
+    base = f"https://www.{domain}/s?k={q}&{dept}"
+    retailer = "Amazon" if locale != "us" else "Amazon Fresh"
+    return GroceryLink(ingredient=ingredient, retailer=retailer, url=wrap_url(base, "amazon"))
 
 
-def _instacart_link(ingredient: str) -> GroceryLink:
+def _instacart_link(ingredient: str, locale: str) -> GroceryLink:
     q = quote_plus(ingredient)
+    if locale == "ca":
+        base = f"https://www.instacart.ca/store/s?k={q}"
+    else:
         base = f"https://www.instacart.com/store/s?k={q}"
     return GroceryLink(ingredient=ingredient, retailer="Instacart", url=wrap_url(base, "instacart"))
 
@@ -50,26 +59,28 @@ def _walmart_link(ingredient: str, affiliate_id: str) -> GroceryLink:
 
 
 class GroceryLinkBuilder:
-    def __init__(self, tier: str = "free", has_byok: bool = False) -> None:
+    def __init__(self, tier: str = "free", has_byok: bool = False, locale: str = "us") -> None:
         self._tier = tier
+        self._locale = locale
+        self._locale_cfg = get_locale(locale)
         self._walmart_id = os.environ.get("WALMART_AFFILIATE_ID", "").strip()
 
     def build_links(self, ingredient: str) -> list[GroceryLink]:
         """Build grocery deeplinks for a single ingredient.
 
-        Amazon Fresh and Instacart links are always included; wrap_url handles
-        affiliate ID injection (or returns a plain URL if none is configured).
-        Walmart requires WALMART_AFFILIATE_ID to be set (Impact network uses a
-        path-based redirect that doesn't degrade cleanly to a plain URL).
+        Amazon link is always included, routed to the user's locale domain.
+        Instacart and Walmart are only shown where they operate (US/CA).
+        wrap_url handles affiliate ID injection for supported programs.
         """
         if not ingredient.strip():
             return []
 
-        links: list[GroceryLink] = [
-            _amazon_fresh_link(ingredient),
-            _instacart_link(ingredient),
-        ]
-        if self._walmart_id:
+        links: list[GroceryLink] = [_amazon_link(ingredient, self._locale)]
+
+        if self._locale_cfg["instacart"]:
+            links.append(_instacart_link(ingredient, self._locale))
+
+        if self._locale_cfg["walmart"] and self._walmart_id:
             links.append(_walmart_link(ingredient, self._walmart_id))
 
         return links

frontend/src/components/SettingsView.vue

@@ -99,6 +99,57 @@
         </div>
       </section>
 
+      <!-- Shopping Locale -->
+      <section class="mt-md">
+        <h3 class="text-lg font-semibold mb-xs">Shopping Region</h3>
+        <p class="text-sm text-secondary mb-sm">
+          Sets your Amazon storefront and which retailers appear in shopping links.
+          Instacart and Walmart are US/CA only — other regions get Amazon.
+        </p>
+        <select
+          class="form-input"
+          v-model="settingsStore.shoppingLocale"
+          aria-label="Shopping region"
+          style="max-width: 20rem;"
+        >
+          <optgroup label="North America">
+            <option value="us">United States (USD $)</option>
+            <option value="ca">Canada (CAD CA$)</option>
+            <option value="mx">Mexico (MXN MX$)</option>
+          </optgroup>
+          <optgroup label="Europe">
+            <option value="gb">United Kingdom (GBP £)</option>
+            <option value="de">Germany (EUR €)</option>
+            <option value="fr">France (EUR €)</option>
+            <option value="it">Italy (EUR €)</option>
+            <option value="es">Spain (EUR €)</option>
+            <option value="nl">Netherlands (EUR €)</option>
+            <option value="se">Sweden (SEK kr)</option>
+          </optgroup>
+          <optgroup label="Asia Pacific">
+            <option value="au">Australia (AUD A$)</option>
+            <option value="nz">New Zealand (NZD NZ$) — via Amazon AU</option>
+            <option value="jp">Japan (JPY ¥)</option>
+            <option value="in">India (INR ₹)</option>
+            <option value="sg">Singapore (SGD S$)</option>
+          </optgroup>
+          <optgroup label="South America">
+            <option value="br">Brazil (BRL R$)</option>
+          </optgroup>
+        </select>
+        <div class="flex-start gap-sm mt-sm">
+          <button
+            class="btn btn-primary btn-sm"
+            :disabled="settingsStore.loading"
+            @click="settingsStore.save()"
+          >
+            <span v-if="settingsStore.loading">Saving…</span>
+            <span v-else-if="settingsStore.saved">✓ Saved!</span>
+            <span v-else>Save</span>
+          </button>
+        </div>
+      </section>
+
       <!-- Display Preferences -->
       <section class="mt-md">
         <h3 class="text-lg font-semibold mb-xs">Display</h3>

frontend/src/services/api.ts

@@ -547,6 +547,7 @@ export interface RecipeRequest {
   wildcard_confirmed: boolean
   nutrition_filters: NutritionFilters
   excluded_ids: number[]
+  exclude_ingredients: string[]
   shopping_mode: boolean
   pantry_match_only: boolean
   complexity_filter: string | null

frontend/src/stores/settings.ts

@@ -13,6 +13,7 @@ export const useSettingsStore = defineStore('settings', () => {
   // State
   const cookingEquipment = ref<string[]>([])
   const unitSystem = ref<UnitSystem>('metric')
+  const shoppingLocale = ref<string>('us')
   const loading = ref(false)
   const saved = ref(false)
 
@@ -20,9 +21,10 @@ export const useSettingsStore = defineStore('settings', () => {
   async function load() {
     loading.value = true
     try {
-      const [rawEquipment, rawUnits] = await Promise.allSettled([
+      const [rawEquipment, rawUnits, rawLocale] = await Promise.allSettled([
         settingsAPI.getSetting('cooking_equipment'),
         settingsAPI.getSetting('unit_system'),
+        settingsAPI.getSetting('shopping_locale'),
       ])
       if (rawEquipment.status === 'fulfilled' && rawEquipment.value) {
         cookingEquipment.value = JSON.parse(rawEquipment.value)
@@ -30,6 +32,9 @@ export const useSettingsStore = defineStore('settings', () => {
       if (rawUnits.status === 'fulfilled' && rawUnits.value) {
         unitSystem.value = rawUnits.value as UnitSystem
       }
+      if (rawLocale.status === 'fulfilled' && rawLocale.value) {
+        shoppingLocale.value = rawLocale.value
+      }
     } catch (err: unknown) {
       console.error('Failed to load settings:', err)
     } finally {
@@ -43,6 +48,7 @@ export const useSettingsStore = defineStore('settings', () => {
       await Promise.all([
         settingsAPI.setSetting('cooking_equipment', JSON.stringify(cookingEquipment.value)),
         settingsAPI.setSetting('unit_system', unitSystem.value),
+        settingsAPI.setSetting('shopping_locale', shoppingLocale.value),
       ])
       saved.value = true
       setTimeout(() => {
@@ -59,6 +65,7 @@ export const useSettingsStore = defineStore('settings', () => {
     // State
     cookingEquipment,
     unitSystem,
+    shoppingLocale,
     loading,
     saved,