ci: Add Asgard runner test workflow

Test workflow to verify act_runner on asgard is operational.

Validates:
- Runner picks up jobs
- Docker container execution
- Go/Rust toolchains available
- System resources (CPU, memory, disk)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.gitea/workflows/test-runner.yml

@@ -0,0 +1,24 @@
+name: Test Asgard Runner
+on: [push]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Test runner capabilities
+        run: |
+          echo "🚀 Running on Asgard!"
+          echo "==========================================="
+          echo "Hostname: $(hostname)"
+          echo "CPU Cores: $(nproc)"
+          echo "Memory: $(free -h | grep Mem | awk '{print $2}')"
+          echo "Disk: $(df -h / | tail -1 | awk '{print $4}')"
+          echo "==========================================="
+          echo "Go: $(go version)"
+          echo "Rust: $(rustc --version)"
+          echo "Docker: $(docker --version)"
+          echo "==========================================="
+          echo "✅ Asgard runner is OPERATIONAL"