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.

views/admin/admissions/partials/tuition-tab.ejs

@@ -0,0 +1,13 @@
+<div class="tab-pane fade <%= activeTab === 'tuition' ? 'show active' : '' %>" id="tuition" role="tabpanel">
+  <div class="card border shadow-sm">
+    <div class="card-header bg-white">
+      <h6 class="mb-0"><i class="fas fa-chart-column me-2"></i>Tuition</h6>
+    </div>
+    <div class="card-body p-4">
+      <div class="page-editor-section" data-section-key="tuition"></div>
+    </div>
+  </div>
+</div>
+
+
+