ci: add release job and package binaries

- Package Linux as tar.gz and Windows as zip
- Include config.yml in releases
- Create GitHub release on push to main with auto-generated tag
- Add contents write permission

.github/workflows/build.yml

@@ -1,4 +1,4 @@
-name: Build
+name: Build & Release
 
 on:
   push:
@@ -6,6 +6,9 @@ on:
   pull_request:
     branches: [main]
 
+permissions:
+  contents: write
+
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -24,10 +27,49 @@ jobs:
         env:
           GOOS: ${{ matrix.goos }}
           GOARCH: ${{ matrix.goarch }}
-        run: go build -o verifactu-api-${{ matrix.goos }}-${{ matrix.goarch }} .
+        run: go build -o verifactu-api .
+
+      - name: Package Linux
+        if: matrix.goos == 'linux'
+        run: |
+          mkdir verifactu-api
+          mv verifactu-api verifactu-api/verifactu-api
+          cp config.yml verifactu-api/
+          tar czf verifactu-api-linux-amd64.tar.gz verifactu-api/
+
+      - name: Package Windows
+        if: matrix.goos == 'windows'
+        run: |
+          mkdir verifactu-api
+          mv verifactu-api.exe verifactu-api/verifactu-api.exe
+          cp config.yml verifactu-api/
+          zip -r verifactu-api-windows-amd64.zip verifactu-api/
 
       - name: Upload artifact
         uses: actions/upload-artifact@v4
         with:
-          name: verifactu-api-${{ matrix.goos }}-${{ matrix.goarch }}
+          name: verifactu-api-${{ matrix.goos }}-amd64
-          path: verifactu-api-${{ matrix.goos }}-${{ matrix.goarch }}
+          path: verifactu-api-${{ matrix.goos }}-amd64.*
+
+  release:
+    needs: build
+    runs-on: ubuntu-latest
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Download artifacts
+        uses: actions/download-artifact@v4
+        with:
+          path: artifacts
+
+      - name: Create release
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          TAG="v$(date +%Y%m%d)-${GITHUB_SHA::7}"
+          gh release create "$TAG" \
+            --title "Build $TAG" \
+            --generate-notes \
+            artifacts/verifactu-api-linux-amd64/* \
+            artifacts/verifactu-api-windows-amd64/*