refactor(policies): migrate to block-based content editor

Replace the legacy section-based policy editor with a flexible block-based system. This transition enables real-time previews, a wider variety of content types (headings, quotes, callouts), and improved data normalization.
- Implement `policies-block-editor.js` for dynamic content management
- Add `normalizePoliciesDocument` and `validateContent` utilities to handle data migration and integrity
- Update `policiesController.js` to support the new block structure and validation logic
- Migrate `policies.json` from `sections` array to a `content.blocks` structure
- Remove obsolete section editor views and partials
- Update `policiesConfig.js` to reflect the new editor capabilities

views/admin/policies/partials/editor-script.ejs

@@ -1,8 +1,8 @@
 <script>
 (function () {
-  const config = window.pageEditorConfig;
-  const initialData = window.pageEditorData;
-  const backendUrl = (window.pageEditorBackendUrl || "").replace(/\/$/, "");
+  const config = readJsonScript("pageEditorConfigData");
+  const initialData = readJsonScript("pageEditorDataPayload");
+  const backendUrl = String(readJsonScript("pageEditorBackendUrlData") || "").replace(/\/$/, "");
   const form = document.getElementById("cmsEditorForm");
   const pageJsonInput = document.getElementById("pageJson");
   const activeTabInput = document.getElementById("activeTabInput");
@@ -52,6 +52,17 @@
     config.tabs.forEach((tab) => renderSection(tab.key));
   }
 
+  function readJsonScript(id) {
+    const node = document.getElementById(id);
+    if (!node) return null;
+    try {
+      return JSON.parse(node.textContent || "null");
+    } catch (error) {
+      console.error(`Failed to parse JSON script "${id}"`, error);
+      return null;
+    }
+  }
+
   function updateTabUrl(tabKey) {
     const url = new URL(window.location.href);
     url.searchParams.set("tab", tabKey);