Add GitHub Actions workflow to build and release dev branch

Automatically builds cloud-hypervisor binary on push to dev branch
and publishes it as a GitHub pre-release.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: CMGS

.github/workflows/dev-release.yaml

@@ -0,0 +1,33 @@
+name: Build and Release Dev
+
+on:
+  push:
+    branches: [dev]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-action/setup@v1
+
+      - name: Build cloud-hypervisor (release)
+        run: cargo build --release
+
+      - name: Upload binary as artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: cloud-hypervisor
+          path: target/release/cloud-hypervisor
+
+      - name: Create dev release
+        uses: softprops/action-gh-release@v2
+        with:
+          tag_name: dev-${{ github.sha }}
+          name: Dev Build ${{ github.sha }}
+          files: target/release/cloud-hypervisor
+          prerelease: true
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}