S3.2: hand-placed 12x12 pixel icon set replaces lucide and reicon

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

package.json

@@ -31,11 +31,9 @@
     "postinstall": "node scripts/ensure-electron.cjs"
   },
   "dependencies": {
-    "lucide-react": "0.468.0",
     "react": "19.2.4",
     "react-dom": "19.2.4",
     "react-markdown": "10.1.0",
-    "reicon-react": "^1.1.2",
     "remark-gfm": "4.0.1",
     "zod": "4.3.6"
   },