feat(loyalty): add dedicated program edit page with full CRUD and tests

Add /admin/loyalty/merchants/{id}/program route for program configuration
with a dedicated Alpine.js edit page supporting create/edit/delete flows.
Restructure programs dashboard with create modal (merchant search +
duplicate detection) and delete confirmation. Rename "Loyalty Settings"
to "Admin Policy" for clearer separation of concerns.

Add integration tests for all admin page routes (12 tests) and program
list search/filter/pagination endpoints (9 tests).

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

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

@@ -99,6 +99,31 @@ async def admin_loyalty_merchant_detail(
     )
 
 
+@router.get(
+    "/merchants/{merchant_id}/program",
+    response_class=HTMLResponse,
+    include_in_schema=False,
+)
+async def admin_loyalty_program_edit(
+    request: Request,
+    merchant_id: int = Path(..., description="Merchant ID"),
+    current_user: User = Depends(require_menu_access("loyalty-programs", FrontendType.ADMIN)),
+    db: Session = Depends(get_db),
+):
+    """
+    Render program configuration edit page for a merchant.
+    Allows admin to create or edit the merchant's loyalty program settings.
+    """
+    return templates.TemplateResponse(
+        "loyalty/admin/program-edit.html",
+        {
+            "request": request,
+            "user": current_user,
+            "merchant_id": merchant_id,
+        },
+    )
+
+
 @router.get(
     "/merchants/{merchant_id}/settings",
     response_class=HTMLResponse,