Add support for multi-platform testing

.github/workflows/go-test.yml

@@ -1,4 +1,4 @@
-name: Go Test
+name: Go Test Multi-Platform
 
 on:
   push:
@@ -13,15 +13,62 @@ permissions:
 
 jobs:
   test:
-    runs-on: ubuntu-latest
+    name: Test (${{ matrix.os }}, ${{ matrix.goarch }})
+    strategy:
+      matrix:
+        include:
+          # AMD64 testing across major platforms
+          - os: ubuntu-latest
+            goarch: amd64
+          - os: windows-latest
+            goarch: amd64
+          - os: macos-latest
+            goarch: amd64
+          # ARM64 testing on supported platforms
+          - os: ubuntu-latest
+            goarch: arm64
+          - os: macos-latest
+            goarch: arm64
+
+    runs-on: ${{ matrix.os }}
+
     steps:
       - name: Checkout Source
-        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744
+        uses: actions/checkout@v4
 
       - name: Set up Go 1.25
-        uses: actions/setup-go@19bb51245e9c80abacb2e91cc42b33fa478b8639
+        uses: actions/setup-go@v4
         with:
           go-version: '1.25'
 
+      - name: Cache Go modules
+        uses: actions/cache@v3
+        with:
+          path: |
+            ~/go/pkg/mod
+            ~/.cache/go-build
+          key: ${{ runner.os }}-go-${{ matrix.goarch }}-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-${{ matrix.goarch }}-
+
       - name: Run Go tests
-        run: go test ./...
+        run: go test -v ./...
+
+      - name: Run Go tests with race detector (Linux AMD64 only)
+        if: matrix.os == 'ubuntu-latest' && matrix.goarch == 'amd64'
+        run: go test -race -v ./...
+
+      - name: Test build (ensure compilation works)
+        run: |
+          # Test that we can build for the current platform
+          echo "Testing build for current platform (${{ matrix.os }}, ${{ matrix.goarch }})..."
+          go build -v ./cmd/reticulum-go
+
+      - name: Test cross-compilation (AMD64 runners only)
+        if: matrix.goarch == 'amd64'
+        run: |
+          echo "Testing ARM64 cross-compilation from AMD64..."
+          GOOS=linux GOARCH=arm64 go build -v ./cmd/reticulum-go
+
+          echo "Testing ARMv6 cross-compilation from AMD64..."
+          GOOS=linux GOARCH=arm GOARM=6 go build -v ./cmd/reticulum-go