fix(loyalty): show category column on card-detail for all 3 personas

The transaction-history table on the card-detail page rendered a
Category column only on the store frontend. Merchant and admin saw
five columns instead of six, even though the merchant report
prompted the audit (rewardflow.lu/merchants/loyalty/cards/6 vs
fashionhub.rewardflow.lu/store/.../cards/6).

Root cause was two layers:
- API: only store's GET /cards/{id}/transactions enriched
  tx.category_names from tx.category_ids; merchant's and admin's
  endpoints returned raw rows with category_names=null.
- Template: the shared partial's show_category_column flag was set
  to true only on the store wrapper.

Backfill the same `category_service.validate_category_for_store`
lookup loop into merchant.py::get_card_transactions and
admin.py::get_merchant_card_transactions, accepting Request to read
request.state.language for localised category names. Add
`{% set show_category_column = true %}` to the merchant and admin
card-detail wrappers.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/modules/loyalty/routes/api/admin.py

@@ -10,7 +10,7 @@ Platform admin endpoints for:
 
 import logging
 
-from fastapi import APIRouter, Depends, Path, Query
+from fastapi import APIRouter, Depends, Path, Query, Request
 from pydantic import BaseModel, Field
 from sqlalchemy.orm import Session
 
@@ -412,6 +412,7 @@ def get_merchant_card(
     response_model=TransactionListResponse,
 )
 def get_merchant_card_transactions(
+    request: Request,
     merchant_id: int = Path(..., gt=0),
     card_id: int = Path(..., gt=0),
     skip: int = Query(0, ge=0),
@@ -430,10 +431,26 @@ def get_merchant_card_transactions(
         db, card_id, skip=skip, limit=limit
     )
 
-    return TransactionListResponse(
-        transactions=[TransactionResponse.model_validate(t) for t in transactions],
-        total=total,
-    )
+    # Enrich category_names from category_ids (same as store + merchant routes
+    # — keeps the transaction history aligned across personas).
+    from app.modules.loyalty.services.category_service import category_service
+
+    lang = getattr(request.state, "language", "en") or "en"
+    tx_responses = []
+    for t in transactions:
+        tx = TransactionResponse.model_validate(t)
+        if t.category_ids and isinstance(t.category_ids, list):
+            names = []
+            for cid in t.category_ids:
+                name = category_service.validate_category_for_store(
+                    db, cid, t.store_id or 0, lang=lang
+                )
+                if name:
+                    names.append(name)
+            tx.category_names = names if names else None
+        tx_responses.append(tx)
+
+    return TransactionListResponse(transactions=tx_responses, total=total)
 
 
 @router.get("/merchants/{merchant_id}/transactions", response_model=TransactionListResponse)

app/modules/loyalty/routes/api/merchant.py

@@ -23,7 +23,7 @@ registration under /api/v1/merchants/loyalty/*).
 
 import logging
 
-from fastapi import APIRouter, Depends, Path, Query
+from fastapi import APIRouter, Depends, Path, Query, Request
 from sqlalchemy.orm import Session
 
 from app.api.deps import get_current_merchant_api, get_merchant_for_current_user
@@ -256,6 +256,7 @@ def get_card_detail(
 
 @router.get("/cards/{card_id}/transactions", response_model=TransactionListResponse)
 def get_card_transactions(
+    request: Request,
     card_id: int = Path(..., gt=0),
     skip: int = Query(0, ge=0),
     limit: int = Query(50, ge=1, le=100),
@@ -271,10 +272,26 @@ def get_card_transactions(
         db, card_id, skip=skip, limit=limit
     )
 
-    return TransactionListResponse(
-        transactions=[TransactionResponse.model_validate(t) for t in transactions],
-        total=total,
-    )
+    # Enrich category_names from category_ids (same as store route — keeps the
+    # transaction history aligned across personas).
+    from app.modules.loyalty.services.category_service import category_service
+
+    lang = getattr(request.state, "language", "en") or "en"
+    tx_responses = []
+    for t in transactions:
+        tx = TransactionResponse.model_validate(t)
+        if t.category_ids and isinstance(t.category_ids, list):
+            names = []
+            for cid in t.category_ids:
+                name = category_service.validate_category_for_store(
+                    db, cid, t.store_id or 0, lang=lang
+                )
+                if name:
+                    names.append(name)
+            tx.category_names = names if names else None
+        tx_responses.append(tx)
+
+    return TransactionListResponse(transactions=tx_responses, total=total)
 
 
 # =============================================================================

app/modules/loyalty/templates/loyalty/admin/merchant-card-detail.html

@@ -17,6 +17,7 @@
 
 {% set card_detail_api_prefix = '/admin/loyalty/merchants/' + merchant_id|string %}
 {% set card_detail_back_url = '/admin/loyalty/merchants/' + merchant_id|string + '/cards' %}
+{% set show_category_column = true %}
 {% include 'loyalty/shared/card-detail-view.html' %}
 {% endblock %}
 

app/modules/loyalty/templates/loyalty/merchant/card-detail.html

@@ -20,6 +20,7 @@
 
 {% set card_detail_api_prefix = '/merchants/loyalty' %}
 {% set card_detail_back_url = '/merchants/loyalty/cards' %}
+{% set show_category_column = true %}
 {% include 'loyalty/shared/card-detail-view.html' %}
 
 {% endblock %}