Fix prod startup mode and add missing y-prosemirror dependency

Frontend/package-lock.json

@@ -35,6 +35,7 @@
         "tailwindcss": "^4.1.18",
         "vue": "^3.5.27",
         "wavesurfer.js": "^7.12.1",
+        "y-prosemirror": "^1.3.7",
         "y-webrtc": "^10.3.0",
         "yjs": "^13.6.29",
         "zod": "^4.1.5"
@@ -23030,6 +23031,30 @@
         "node": ">=12"
       }
     },
+    "node_modules/y-prosemirror": {
+      "version": "1.3.7",
+      "resolved": "https://registry.npmjs.org/y-prosemirror/-/y-prosemirror-1.3.7.tgz",
+      "integrity": "sha512-NpM99WSdD4Fx4if5xOMDpPtU3oAmTSjlzh5U4353ABbRHl1HtAFUx6HlebLZfyFxXN9jzKMDkVbcRjqOZVkYQg==",
+      "license": "MIT",
+      "dependencies": {
+        "lib0": "^0.2.109"
+      },
+      "engines": {
+        "node": ">=16.0.0",
+        "npm": ">=8.0.0"
+      },
+      "funding": {
+        "type": "GitHub Sponsors ❤",
+        "url": "https://github.com/sponsors/dmonad"
+      },
+      "peerDependencies": {
+        "prosemirror-model": "^1.7.1",
+        "prosemirror-state": "^1.2.3",
+        "prosemirror-view": "^1.9.10",
+        "y-protocols": "^1.0.1",
+        "yjs": "^13.5.38"
+      }
+    },
     "node_modules/y-protocols": {
       "version": "1.0.7",
       "resolved": "https://registry.npmjs.org/y-protocols/-/y-protocols-1.0.7.tgz",

Frontend/package.json

@@ -48,6 +48,7 @@
     "tailwindcss": "^4.1.18",
     "vue": "^3.5.27",
     "wavesurfer.js": "^7.12.1",
+    "y-prosemirror": "^1.3.7",
     "y-webrtc": "^10.3.0",
     "yjs": "^13.6.29",
     "zod": "^4.1.5"