Move CI to Gitea Actions

Single-runner workflow: test on every push; on v* tags cross-compile tefterd
for all platforms, build the Linux desktop app, and publish a Gitea release
via gitea.com/actions/release-action. Drop the GitHub workflow; document the
runner requirement and manual macOS/Windows desktop builds in the README.

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

.gitea/workflows/ci.yml

@@ -0,0 +1,72 @@
+name: ci
+
+# Gitea Actions (repo has Actions enabled; needs one Linux runner whose
+# `ubuntu-latest` label maps to a Debian/Ubuntu-based image, e.g. the default
+# catthehacker/ubuntu:act-latest). Everything runs on that single runner:
+# tefterd is CGO-free and cross-compiles to all four platforms from Linux.
+# The macOS/Windows *desktop* shells can't be built on a Linux runner — build
+# those manually with `make desktop` on such a machine (see README).
+
+on:
+  push:
+    branches: ['**']
+    tags: ['v*']
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with: { go-version: 'stable' }
+      - uses: actions/setup-node@v4
+        with: { node-version: '22' }
+      - name: Build frontend
+        run: make frontend
+      - name: Embed bundle
+        run: rm -rf server/webdist/dist && cp -r frontend/dist server/webdist/dist
+      - name: Vet + tests
+        run: cd server && go vet ./... && go test ./...
+      - name: Type-check frontend
+        run: cd frontend && npx svelte-check --tsconfig ./tsconfig.json
+
+  release:
+    needs: test
+    if: startsWith(github.ref, 'refs/tags/')
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with: { go-version: 'stable' }
+      - uses: actions/setup-node@v4
+        with: { node-version: '22' }
+      - name: Desktop build deps (GTK/WebKit)
+        run: |
+          if command -v sudo >/dev/null; then SUDO=sudo; else SUDO=; fi
+          $SUDO apt-get update
+          $SUDO apt-get install -y --no-install-recommends \
+            build-essential pkg-config libgtk-3-dev libwebkit2gtk-4.1-dev libx11-dev
+      - name: Install Wails CLI
+        run: go install github.com/wailsapp/wails/v2/cmd/wails@latest
+      - name: Build tefterd for all platforms
+        run: make server-all VERSION=${{ github.ref_name }}
+      - name: Build desktop (linux/amd64)
+        run: |
+          rm -rf desktop/frontend/dist
+          cp -r frontend/dist desktop/frontend/dist
+          cd desktop && PATH="$PATH:$(go env GOPATH)/bin" \
+            wails build -tags webkit2_41 -ldflags "-X main.Version=${{ github.ref_name }}"
+      - name: Package artifacts
+        run: |
+          mkdir -p out pkg
+          cp build/tefterd-* out/
+          cp desktop/build/bin/tefter-desktop pkg/
+          cp desktop/tefter.desktop pkg/
+          cp frontend/public/icon-512.png pkg/tefter.png
+          tar -C pkg -czf out/tefter-desktop-linux-amd64.tar.gz .
+          ls -la out/
+      - name: Create Gitea release
+        uses: https://gitea.com/actions/release-action@main
+        with:
+          files: out/**
+          api_key: '${{ secrets.GITHUB_TOKEN }}'