feat(docker): dodaj opcjonalne uruchomienie testów podczas buildu

Dodano build arg RUN_TESTS (domyślnie false), który pozwala na
warunkowe uruchomienie quality checks (typecheck + lint) podczas
budowania obrazu Docker.

Użycie:
- Bez testów: docker build -t rentgen .
- Z testami: docker build --build-arg RUN_TESTS=true -t rentgen .

Testy dodają ~10 sekund do czasu buildu.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Dockerfile

@@ -4,6 +4,9 @@
 #   Build and extract artifacts directly:
 #     docker buildx build . --output artifacts
 #
+#   Build with tests (typecheck + lint):
+#     docker build --build-arg RUN_TESTS=true -t rentgen .
+#
 #   Or traditional build (creates full development environment):
 #     docker build -t rentgen .
 #     docker run --rm rentgen ls -lh /app/web-ext-artifacts/
@@ -15,6 +18,9 @@
 # Build stage
 FROM node:lts AS builder
 
+# Optional: run tests during build (typecheck + lint)
+ARG RUN_TESTS=false
+
 WORKDIR /app
 
 # Copy package files for dependency installation (better layer caching)
@@ -32,6 +38,14 @@ RUN npm run build
 # Create the package
 RUN npm run create-package
 
+# Optional: run quality checks
+RUN if [ "$RUN_TESTS" = "true" ]; then \
+        echo "Running TypeScript type checking..."; \
+        npm run typecheck; \
+        echo "Running web-ext lint..."; \
+        npm run lint; \
+    fi
+
 # Artifacts stage - only contains the built artifacts (for --output)
 FROM scratch AS artifacts