fix: ranking refresh deadlock, switch to direct HTTP, add CI pipeline

- Fix channel drain goroutine deadlock in handleRankingRefresh: replace
  'for { ... continue ... if nil break }' with 'for A != nil || B != nil'
  so the select never blocks on two nil channels
- Switch ScrapeRanking from urlClient (Browserless) to client (direct HTTP)
  since novelfire.net/ranking is fully server-rendered — no JS needed
- Add ranking unit tests (single page, multi-page, empty page, write round-trip)
- Add .gitea/workflows/ci.yaml: lint, test, build jobs with commented-out
  Docker image push step for when runner has Docker available

.gitea/workflows/ci.yaml

@@ -0,0 +1,106 @@
+name: CI
+
+on:
+  push:
+    branches: ["main", "master"]
+    paths:
+      - "scraper/**"
+      - ".gitea/workflows/**"
+  pull_request:
+    branches: ["main", "master"]
+    paths:
+      - "scraper/**"
+      - ".gitea/workflows/**"
+
+defaults:
+  run:
+    working-directory: scraper
+
+jobs:
+  # ── lint & vet ───────────────────────────────────────────────────────────────
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: scraper/go.mod
+          cache-dependency-path: scraper/go.sum
+
+      - name: go vet
+        run: go vet ./...
+
+      - name: staticcheck
+        run: |
+          go install honnef.co/go/tools/cmd/staticcheck@latest
+          staticcheck ./...
+
+  # ── tests ────────────────────────────────────────────────────────────────────
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: scraper/go.mod
+          cache-dependency-path: scraper/go.sum
+
+      - name: Run tests
+        run: go test -race -count=1 -timeout=60s ./...
+
+  # ── build binary ─────────────────────────────────────────────────────────────
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    needs: [lint, test]
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: scraper/go.mod
+          cache-dependency-path: scraper/go.sum
+
+      - name: Build binary
+        run: |
+          CGO_ENABLED=0 GOOS=linux GOARCH=amd64 \
+            go build -ldflags="-s -w" -o bin/scraper ./cmd/scraper
+
+      - name: Upload binary artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: scraper-linux-amd64
+          path: scraper/bin/scraper
+          retention-days: 7
+
+  # ── docker build (& push) ────────────────────────────────────────────────────
+  # Uncomment once the runner has Docker available and a registry is configured.
+  #
+  # docker:
+  #   name: Docker
+  #   runs-on: ubuntu-latest
+  #   needs: [lint, test]
+  #   # Only push images on commits to the default branch, not on PRs.
+  #   # if: github.event_name == 'push'
+  #   steps:
+  #     - uses: actions/checkout@v4
+  #
+  #     - name: Log in to Gitea registry
+  #       uses: docker/login-action@v3
+  #       with:
+  #         registry: gitea.kalekber.cc
+  #         username: ${{ secrets.REGISTRY_USER }}
+  #         password: ${{ secrets.REGISTRY_TOKEN }}
+  #
+  #     - name: Build and push
+  #       uses: docker/build-push-action@v5
+  #       with:
+  #         context: ./scraper
+  #         push: true
+  #         tags: |
+  #           gitea.kalekber.cc/kamil/libnovel:latest
+  #           gitea.kalekber.cc/kamil/libnovel:${{ gitea.sha }}