ci: GitHub Actions 워크플로우 추가

Windows Go 빌드 자동화 (push/PR on main)

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

.github/workflows/ci.yml

@@ -0,0 +1,21 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  build:
+    # Windows runner required for Win32 API dependencies
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.24'
+
+      - name: Build
+        run: go build -ldflags="-H windowsgui -s -w" -o launcher.exe .