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/templates_config.py

@@ -15,6 +15,7 @@ Module templates should use namespace prefix to avoid collisions:
 """
 
 import logging
+from datetime import datetime
 from pathlib import Path
 
 from fastapi.templating import Jinja2Templates
@@ -92,3 +93,4 @@ templates.env.globals["SUPPORTED_LANGUAGES"] = SUPPORTED_LANGUAGES
 templates.env.globals["DEFAULT_LANGUAGE"] = DEFAULT_LANGUAGE
 templates.env.globals["LANGUAGE_NAMES"] = LANGUAGE_NAMES
 templates.env.globals["LANGUAGE_FLAGS"] = LANGUAGE_FLAGS
+templates.env.globals["current_year"] = datetime.now().year