feat: add WSL 2 + Docker for Linux container builds on Windows CI

Install Ubuntu 24.04 in WSL, set up Docker Engine inside it, and use
it to build and verify the Linux Docker image on the Windows runner.
No third-party actions required — uses native wsl commands.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: JonZeolla

.github/workflows/ci.yml

@@ -229,6 +229,35 @@ jobs:
         run: |
           cd "$RUNNER_TEMP/replace-me"
           task -v unit-test
+      - name: Setup WSL with Docker
+        shell: bash
+        run: |
+          wsl --install -d Ubuntu-24.04 --no-launch
+          wsl -d Ubuntu-24.04 -u root -- bash -ec "
+            apt-get update -qq
+            apt-get install -y -qq curl ca-certificates >/dev/null
+            curl -fsSL https://get.docker.com | sh -s -- --quiet
+            service docker start
+            docker buildx create --use
+          "
+      - name: Build Docker image
+        shell: bash
+        run: |
+          wsl_project="$(wsl -d Ubuntu-24.04 -- wslpath "$RUNNER_TEMP")/replace-me"
+          wsl -d Ubuntu-24.04 -u root --cd "$wsl_project" -- docker buildx build \
+            --platform linux/amd64 \
+            --pull --load \
+            --build-arg NAME=replace_me \
+            --build-arg "DESCRIPTION=A brief description of the project" \
+            --build-arg "TIMESTAMP=$(date -u +%Y-%m-%dT%H:%M:%SZ)" \
+            --build-arg COMMIT_HASH=smoke-test \
+            -t zenable-io/replace-me:latest .
+      - name: Verify Docker image
+        shell: bash
+        run: |
+          wsl -d Ubuntu-24.04 -u root -- docker run --rm --entrypoint python3 \
+            zenable-io/replace-me:latest \
+            -c "from replace_me import __version__; print(__version__)"
       - name: Verify zenable CLI
         shell: bash
         run: |