fix: md editor doing round-trip html-md-html on save

package.json

@@ -31,6 +31,7 @@
     "bump": "node scripts/sync-version.js --bump",
     "bump:minor": "node scripts/sync-version.js --bump --minor",
     "bump:major": "node scripts/sync-version.js --bump --major",
+    "prebuild": "npm run clean",
     "build": "tsc && shx cp setup-claude-server.js uninstall-claude-server.js track-installation.js dist/ && shx chmod +x dist/*.js && shx mkdir -p dist/data && shx cp src/data/onboarding-prompts.json dist/data/ && shx mkdir -p dist/remote-device/scripts && shx cp src/remote-device/scripts/blocking-offline-update.js dist/remote-device/scripts/ && node scripts/build-ui-runtime.cjs",
     "watch": "tsc --watch",
     "start": "node dist/index.js",
@@ -84,13 +85,14 @@
     "file-operations"
   ],
   "dependencies": {
+    "@codemirror/commands": "^6.10.3",
+    "@codemirror/lang-markdown": "^6.5.0",
+    "@codemirror/state": "^6.6.0",
+    "@codemirror/view": "^6.41.1",
+    "@lezer/markdown": "^1.6.3",
     "@modelcontextprotocol/sdk": "^1.9.0",
     "@opendocsg/pdf2md": "^0.2.2",
     "@supabase/supabase-js": "^2.89.0",
-    "@tiptap/core": "^3.22.3",
-    "@tiptap/extension-image": "^3.22.3",
-    "@tiptap/pm": "^3.22.3",
-    "@tiptap/starter-kit": "^3.22.3",
     "@vscode/ripgrep": "^1.15.9",
     "cross-fetch": "^4.1.0",
     "exceljs": "^4.4.0",
@@ -99,17 +101,11 @@
     "glob": "^10.3.10",
     "highlight.js": "^11.11.1",
     "isbinaryfile": "^5.0.4",
-    "markdown-it": "^14.1.0",
     "md-to-pdf": "^5.2.5",
     "open": "^10.2.0",
     "pdf-lib": "^1.17.1",
     "pizzip": "^3.2.0",
-    "remark": "^15.0.1",
-    "remark-gfm": "^4.0.1",
-    "remark-parse": "^11.0.0",
     "sharp": "^0.34.5",
-    "tiptap-markdown": "^0.9.0",
-    "unified": "^11.0.5",
     "unpdf": "^1.4.0",
     "zod": "^3.24.1",
     "zod-to-json-schema": "^3.23.5"

src/ui/file-preview/src/markdown/conflict-dialog.ts

@@ -2,7 +2,7 @@
  * The "file changed on disk" conflict resolver.
  *
  * Shown when saveDocument detected that disk differs from what the editor
- * thought it had. The editor has already re-synced its sourceContent to the
+ * thought it had. The editor has already re-synced its disk baseline to the
  * fresh disk content with keepDraft: true — so the dialog's two actions map
  * onto concrete state transitions:
  *