Add reusable read-only CodeMirror source viewer

packages/block-editor/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/block-editor",
-  "version": "0.1.12",
+  "version": "0.1.15",
   "type": "module",
   "description": "Hydrated accessible editor runtime for WRNexus block documents.",
   "exports": {
@@ -16,9 +16,15 @@
     "typecheck": "tsc --noEmit"
   },
   "dependencies": {
+    "@codemirror/lang-xml": "6.1.0",
+    "@codemirror/language": "6.12.4",
+    "@codemirror/state": "6.7.4",
+    "@codemirror/view": "6.43.11",
+    "@lezer/highlight": "1.2.3",
     "@wrnexus/blocks": "workspace:*",
     "@wrnexus/dnd": "workspace:*",
-    "@wrnexus/reactive": "workspace:*"
+    "@wrnexus/reactive": "workspace:*",
+    "codemirror": "6.0.2"
   },
   "devDependencies": {
     "@types/bun": "^1.4.0",