Add Forgejo CI/CD workflows with self-hosted runners

- Convert GitHub Actions workflow to Forgejo format
- Configure workflows to run on self-hosted runners
- Maintain existing build pipeline with Node.js 20 and 22 matrix
- Include type checking, linting, and build steps
- Upload build artifacts for both Node.js versions

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

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

.forgejo/workflows/build.yml

@@ -0,0 +1,47 @@
+name: Lint and Build
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    runs-on: self-hosted
+
+    strategy:
+      matrix:
+        node-version: [ 20, 22 ]
+
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v4
+
+      - name: Set up Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: 'npm'
+
+      - name: Clean NextJS cache
+        run: rm -rf .next
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run type check
+        run: npm run type-check
+
+      - name: Run linter
+        run: npm run lint
+
+      - name: Build project
+        run: npm run build
+
+      - name: Upload Build Artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: obs-ss-${{ matrix.node-version }}
+          include-hidden-files: 'true'
+          path: ./.next/*