feat(cms): refactor page content management and implement detailed editors

Refactor the CMS page content system to use a more modular configuration-driven approach. This replaces the monolithic `pageContentConfig.js` with individual configuration files for each page and introduces a shared field utility to standardize editor components.
Key changes:
- Implement a generic `_renderSingletonPageView` helper to reduce duplication across controllers.
- Enhance `_createPageContentController` with `normalizeForEditor`, `normalizeForApi`, and `preparePayload` hooks for custom data transformation.
- Create dedicated configuration and view structures for Partnerships, History, Accreditation, Admissions, and Policies pages.
- Add a specialized section editor for Policies to manage complex nested content.
- Improve the frontend `page-content-editor.js` with support for visibility logic, auto-sequencing for arrays, and URL synchronization for active tabs.
- Update data JSON files to align with the new schema.

data/policies.json

@@ -5,7 +5,7 @@
     "titlePrefix": "Our Commitment to",
     "titleHighlight": "Transparency",
     "description": "Review our policies, terms of service, and commitments to privacy and accessibility. We believe in clear, straightforward communication with our academic community.",
-    "lastUpdated": "Last updated: September 15, 2025"
+    "lastUpdated": "Last updated: April 20, 2026"
   },
   "sidebar": {
     "heading": "Policies",
@@ -175,4 +175,4 @@
       ]
     }
   ]
-}
+}