refactor(platform): make base template fully CMS-driven and platform-aware

Remove all hardcoded OMS-specific content from platform base template:
nav links, contact info, brand name, and footer columns. Everything is
now dynamic via platform model and CMS page queries. Wire up legal_pages
context (privacy/terms) from database instead of hardcoded fallback.

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

app/modules/cms/services/content_page_service.py

@@ -282,6 +282,7 @@ class ContentPageService:
         include_unpublished: bool = False,
         footer_only: bool = False,
         header_only: bool = False,
+        legal_only: bool = False,
     ) -> list[ContentPage]:
         """
         List platform marketing pages.
@@ -292,6 +293,7 @@ class ContentPageService:
             include_unpublished: Include draft pages
             footer_only: Only pages marked for footer display
             header_only: Only pages marked for header display
+            legal_only: Only legal pages (privacy, terms) — not in header or footer nav
 
         Returns:
             List of platform marketing ContentPage objects
@@ -311,6 +313,9 @@ class ContentPageService:
         if header_only:
             filters.append(ContentPage.show_in_header == True)
 
+        if legal_only:
+            filters.append(ContentPage.slug.in_(["privacy", "terms"]))
+
         return (
             db.query(ContentPage)
             .filter(and_(*filters))