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/definition.py

@@ -45,6 +45,7 @@ def _get_platform_context(request: Any, db: Any, platform: Any) -> dict[str, Any
 
     header_pages = []
     footer_pages = []
+    legal_pages = []
 
     try:
         header_pages = content_page_service.list_platform_pages(
@@ -53,8 +54,11 @@ def _get_platform_context(request: Any, db: Any, platform: Any) -> dict[str, Any
         footer_pages = content_page_service.list_platform_pages(
             db, platform_id=platform_id, footer_only=True, include_unpublished=False
         )
+        legal_pages = content_page_service.list_platform_pages(
+            db, platform_id=platform_id, legal_only=True, include_unpublished=False
+        )
         logger.debug(
-            f"[CMS] Platform context: {len(header_pages)} header, {len(footer_pages)} footer pages"
+            f"[CMS] Platform context: {len(header_pages)} header, {len(footer_pages)} footer, {len(legal_pages)} legal pages"
         )
     except Exception as e:
         logger.warning(f"[CMS] Failed to load platform navigation pages: {e}")
@@ -62,7 +66,7 @@ def _get_platform_context(request: Any, db: Any, platform: Any) -> dict[str, Any
     return {
         "header_pages": header_pages,
         "footer_pages": footer_pages,
-        "legal_pages": [],  # TODO: Add legal pages support if needed
+        "legal_pages": legal_pages,
     }