Add Gitea Actions: CI tests and package release workflow

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -0,0 +1,17 @@
+name: CI
+
+on:
+  push:
+    branches: ['**']
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+      - run: go vet ./...
+      - run: go test ./...

.gitea/workflows/release.yml

@@ -0,0 +1,34 @@
+name: Release
+
+on:
+  push:
+    tags: ['v*.*.*']
+
+jobs:
+  build-and-publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+
+      - name: Build
+        run: make dist VERSION=${GITEA_REF_NAME#v}
+        env:
+          GITEA_REF_NAME: ${{ gitea.ref_name }}
+
+      - name: Publish to package registry
+        env:
+          VERSION: ${{ gitea.ref_name }}
+          TOKEN: ${{ secrets.PACKAGE_TOKEN }}
+          BASE: ${{ gitea.server_url }}/api/packages/${{ gitea.repository_owner }}/generic/hotpcalc
+        run: |
+          set -e
+          for f in dist/*; do
+            name=$(basename "$f")
+            echo "upload: $name"
+            curl -fsSL -H "Authorization: token ${TOKEN}" \
+              --upload-file "$f" \
+              "${BASE}/${VERSION#v}/${name}"
+          done