Add MoQ image build workflow

Build and verify MoQ images on amd64 and arm64 pull requests, and document MoQ Docker build and runtime configuration.

.github/workflows/moq-build.yml

@@ -0,0 +1,32 @@
+name: Build MoQ image
+
+on:
+  pull_request:
+    paths:
+      - Dockerfile.moq
+      - machinery/**
+      - ui/**
+      - .github/workflows/moq-build.yml
+  workflow_dispatch:
+
+jobs:
+  build:
+    name: MoQ (${{ matrix.architecture }})
+    runs-on: ${{ matrix.runner }}
+    strategy:
+      matrix:
+        include:
+          - architecture: amd64
+            runner: ubuntu-24.04
+          - architecture: arm64
+            runner: ubuntu-24.04-arm
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Build image
+        run: docker build --file Dockerfile.moq --tag agent-moq:${{ matrix.architecture }} .
+
+      - name: Verify binary
+        run: docker run --rm agent-moq:${{ matrix.architecture }} ./main -action version