Fix CI build failures on self-hosted runners

- Move bufferutil to optionalDependencies (not required for core functionality)
- Add --no-optional flag to npm ci in workflow to skip native dependencies
- This avoids needing C++ build tools on CI runners

The bufferutil package is a performance optimization for WebSocket but not required.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

.forgejo/workflows/build.yml

@@ -19,7 +19,7 @@ jobs:
         run: rm -rf .next
 
       - name: Install dependencies
-        run: npm ci
+        run: npm ci --no-optional
 
       - name: Run type check
         run: npm run type-check

package.json

@@ -16,7 +16,6 @@
   },
   "dependencies": {
     "@tailwindcss/postcss": "^4.1.11",
-    "bufferutil": "^4.0.8",
     "next": "^15.4.1",
     "obs-websocket-js": "^5.0.6",
     "react": "^19.1.0",
@@ -25,6 +24,9 @@
     "sqlite3": "^5.1.7",
     "ws": "^8.18.0"
   },
+  "optionalDependencies": {
+    "bufferutil": "^4.0.8"
+  },
   "devDependencies": {
     "@tailwindcss/forms": "^0.5.10",
     "@testing-library/jest-dom": "^6.6.3",