Adds the Offerings module and retargets the CI/CD pipeline to Api.SlpSoftware

Implements Unit 2 "Offerings" (backend module, admin CRUD UI with
drag-and-drop reordering, public GET /api/v1/offerings endpoint) and
executes the feature's D-15 CI/CD cutover, switching the deploy
pipeline's build/publish target from SlpModularCms.Api to
SlpModularCms.Api.SlpSoftware.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FWyStNL2ZsjrS7FLd7xvvN

frontend/src/i18n/locales/nl/translation.json

@@ -10,6 +10,7 @@
         "dashboard": "Dashboard",
         "users": "Gebruikers",
         "cms": "CMS",
+        "offerings": "Aanbiedingen",
         "profile": "Profiel",
         "settings": "Instellingen",
         "openMenu": "Navigatie openen",
@@ -230,6 +231,50 @@
             "successUnreachableToast": "Status opgeslagen — cliënt niet bereikbaar"
         }
     },
+    "offerings": {
+        "title": "Aanbiedingen",
+        "addButton": "Aanbieding toevoegen",
+        "emptyState": {
+            "heading": "Nog geen aanbiedingen",
+            "description": "Voeg je eerste aanbieding toe om te beginnen."
+        },
+        "table": {
+            "title": "Titel",
+            "price": "Prijs",
+            "featured": "Uitgelicht",
+            "actions": "Acties"
+        },
+        "actions": {
+            "drag": "Sleep om te herordenen",
+            "edit": "Bewerken",
+            "delete": "Verwijderen",
+            "moveUp": "Omhoog verplaatsen",
+            "moveDown": "Omlaag verplaatsen",
+            "markFeatured": "Markeren als uitgelicht",
+            "unmarkFeatured": "Uitgelicht verwijderen"
+        },
+        "deleteDialog": {
+            "title": "Aanbieding verwijderen",
+            "message": "Weet je zeker dat je '{{title}}' wilt verwijderen?",
+            "confirmButton": "Verwijderen",
+            "cancelButton": "Annuleren"
+        },
+        "form": {
+            "createTitle": "Nieuwe aanbieding",
+            "editTitle": "Aanbieding bewerken",
+            "titleLabel": "Titel",
+            "descriptionLabel": "Beschrijving",
+            "priceLabel": "Prijs",
+            "priceNoteLabel": "Prijsnotitie",
+            "featuresLabel": "Kenmerken",
+            "addFeatureButton": "Kenmerk toevoegen",
+            "removeFeatureButton": "Verwijderen",
+            "ctaLabelLabel": "Knoptekst",
+            "featuredLabel": "Uitgelicht",
+            "submitButton": "Opslaan",
+            "successToast": "Aanbieding succesvol opgeslagen"
+        }
+    },
     "error": {
         "403": {
             "title": "Toegang geweigerd",