fix: loyalty module end-to-end — merchant route, store menus, sidebar, API error handling

- Add merchant loyalty overview route and template (was 404)
- Fix store loyalty route paths to match menu URLs (/{store_code}/loyalty/...)
- Add loyalty rewards card to storefront account dashboard
- Fix merchant overview to resolve merchant via get_merchant_for_current_user_page
- Fix store login to use store's primary platform for JWT token (interim fix)
- Fix apiClient to attach status/errorCode to thrown errors (fixes error.status
  checks in 12+ JS files — loyalty settings, terminal, email templates, etc.)
- Hide "Add Product" sidebar button when catalog module is not enabled
- Add proposal doc for proper platform detection in store login flow

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/modules/loyalty/routes/pages/store.py

@@ -7,12 +7,15 @@ Store pages for:
 - Loyalty members management
 - Program settings
 - Stats dashboard
+
+Routes follow the standard store convention: /{store_code}/loyalty/...
+so they match the menu URLs in definition.py.
 """
 
 import logging
 
 from fastapi import APIRouter, Depends, Path, Request
-from fastapi.responses import HTMLResponse
+from fastapi.responses import HTMLResponse, RedirectResponse
 from sqlalchemy.orm import Session
 
 from app.api.deps import get_current_store_from_cookie_or_header, get_db
@@ -27,8 +30,9 @@ logger = logging.getLogger(__name__)
 router = APIRouter()
 
 # Route configuration for module route discovery
+# No custom prefix — routes include /loyalty/ in their paths to follow
+# the standard store convention: /store/{store_code}/loyalty/...
 ROUTE_CONFIG = {
-    "prefix": "/loyalty",
     "tags": ["store-loyalty"],
 }
 
@@ -76,13 +80,37 @@ def get_store_context(
     return context
 
 
+# ============================================================================
+# LOYALTY ROOT (Redirect to Terminal)
+# ============================================================================
+
+
+@router.get(
+    "/{store_code}/loyalty",
+    response_class=RedirectResponse,
+    include_in_schema=False,
+)
+async def store_loyalty_root(
+    store_code: str = Path(..., description="Store code"),
+    current_user: User = Depends(get_current_store_from_cookie_or_header),
+):
+    """
+    Redirect loyalty root to the terminal (primary daily interface).
+    Menu item "Dashboard" points here.
+    """
+    return RedirectResponse(
+        url=f"/store/{store_code}/loyalty/terminal",
+        status_code=302,
+    )
+
+
 # ============================================================================
 # LOYALTY TERMINAL (Primary Daily Interface)
 # ============================================================================
 
 
 @router.get(
-    "/{store_code}/terminal",
+    "/{store_code}/loyalty/terminal",
     response_class=HTMLResponse,
     include_in_schema=False,
 )
@@ -108,7 +136,7 @@ async def store_loyalty_terminal(
 
 
 @router.get(
-    "/{store_code}/cards",
+    "/{store_code}/loyalty/cards",
     response_class=HTMLResponse,
     include_in_schema=False,
 )
@@ -129,7 +157,7 @@ async def store_loyalty_cards(
 
 
 @router.get(
-    "/{store_code}/cards/{card_id}",
+    "/{store_code}/loyalty/cards/{card_id}",
     response_class=HTMLResponse,
     include_in_schema=False,
 )
@@ -156,7 +184,7 @@ async def store_loyalty_card_detail(
 
 
 @router.get(
-    "/{store_code}/settings",
+    "/{store_code}/loyalty/settings",
     response_class=HTMLResponse,
     include_in_schema=False,
 )
@@ -182,7 +210,7 @@ async def store_loyalty_settings(
 
 
 @router.get(
-    "/{store_code}/stats",
+    "/{store_code}/loyalty/stats",
     response_class=HTMLResponse,
     include_in_schema=False,
 )
@@ -208,7 +236,7 @@ async def store_loyalty_stats(
 
 
 @router.get(
-    "/{store_code}/enroll",
+    "/{store_code}/loyalty/enroll",
     response_class=HTMLResponse,
     include_in_schema=False,
 )