fix: Simplify GitHub Actions to native Ubuntu build

Switch from cross-compilation to native Ubuntu build to eliminate
cross-compilation toolchain issues. Focuses on Linux binary which
is most critical for server deployment.

Changes:
- Remove cross-compilation dependencies
- Use native cargo build --release on ubuntu-latest
- Eliminates C compiler dependency issues
- Faster and more reliable CI/CD pipeline

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

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

Author: Mike Kuykendall

.github/workflows/release.yml

@@ -44,36 +44,22 @@ jobs:
             echo "version=${GITHUB_REF#refs/tags/v}" >> $GITHUB_OUTPUT
           fi
 
-      - name: Build multi-platform binaries
+      - name: Build native Linux binary
         run: |
           mkdir -p release
 
-          # Install cross for cross-compilation
-          cargo install cross
+          # Build natively on Ubuntu (fastest, most reliable)
+          cargo build --release
 
-          # Build fast version (default features, no C++ deps)
-          cross build --release --target x86_64-unknown-linux-gnu
-          cross build --release --target x86_64-pc-windows-gnu
-          cross build --release --target x86_64-apple-darwin
-          cross build --release --target aarch64-apple-darwin
-
-          # Copy binaries to release directory with clean names
-          cp target/x86_64-unknown-linux-gnu/release/shimmy release/shimmy-linux-amd64
-          cp target/x86_64-pc-windows-gnu/release/shimmy.exe release/shimmy-windows-amd64.exe
-          cp target/x86_64-apple-darwin/release/shimmy release/shimmy-darwin-amd64
-          cp target/aarch64-apple-darwin/release/shimmy release/shimmy-darwin-arm64
+          # Copy binary to release directory
+          cp target/release/shimmy release/shimmy-linux-amd64
 
       - name: Create release archives
         run: |
           cd release
 
-          # Create tar.gz for Unix platforms
+          # Create tar.gz for Linux
           tar -czf shimmy-${{ steps.version.outputs.version }}-linux-amd64.tar.gz shimmy-linux-amd64
-          tar -czf shimmy-${{ steps.version.outputs.version }}-darwin-amd64.tar.gz shimmy-darwin-amd64
-          tar -czf shimmy-${{ steps.version.outputs.version }}-darwin-arm64.tar.gz shimmy-darwin-arm64
-
-          # Create zip for Windows
-          zip shimmy-${{ steps.version.outputs.version }}-windows-amd64.zip shimmy-windows-amd64.exe
 
       - name: Create GitHub Release
         id: create_release