fix: add OCR image to CI/CD workflows (refs #64)

- Add OCR image build/push to staging workflow
- Add OCR service with image override to staging compose
- Add OCR service with image override to blue-green compose
- Add OCR image pull/deploy to production workflow
- Include mvp-ocr-staging in health checks

The OCR container is a shared service (like postgres/redis),
not part of blue-green deployment.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitea/workflows/production.yaml

@@ -34,6 +34,7 @@ jobs:
       target_stack: ${{ steps.determine-stack.outputs.target_stack }}
       backend_image: ${{ steps.set-images.outputs.backend_image }}
       frontend_image: ${{ steps.set-images.outputs.frontend_image }}
+      ocr_image: ${{ steps.set-images.outputs.ocr_image }}
     steps:
       - name: Check Docker availability
         run: |
@@ -53,6 +54,7 @@ jobs:
           TAG="${{ inputs.image_tag }}"
           echo "backend_image=$REGISTRY/egullickson/backend:$TAG" >> $GITHUB_OUTPUT
           echo "frontend_image=$REGISTRY/egullickson/frontend:$TAG" >> $GITHUB_OUTPUT
+          echo "ocr_image=$REGISTRY/egullickson/ocr:$TAG" >> $GITHUB_OUTPUT
 
       - name: Determine target stack
         id: determine-stack
@@ -83,6 +85,7 @@ jobs:
       TARGET_STACK: ${{ needs.validate.outputs.target_stack }}
       BACKEND_IMAGE: ${{ needs.validate.outputs.backend_image }}
       FRONTEND_IMAGE: ${{ needs.validate.outputs.frontend_image }}
+      OCR_IMAGE: ${{ needs.validate.outputs.ocr_image }}
     steps:
       - name: Checkout scripts, config, and compose files
         uses: actions/checkout@v4
@@ -138,6 +141,7 @@ jobs:
         run: |
           docker pull $BACKEND_IMAGE
           docker pull $FRONTEND_IMAGE
+          docker pull $OCR_IMAGE
 
       - name: Record expected image IDs
         id: expected-images
@@ -155,10 +159,12 @@ jobs:
           cd "$DEPLOY_PATH"
           export BACKEND_IMAGE=$BACKEND_IMAGE
           export FRONTEND_IMAGE=$FRONTEND_IMAGE
+          export OCR_IMAGE=$OCR_IMAGE
           # --force-recreate ensures containers are recreated even if image tag is same
           # This prevents stale container content when image digest changes
+          # Start shared OCR service and target stack
           docker compose -f $COMPOSE_FILE -f $COMPOSE_BLUE_GREEN up -d --force-recreate \
-            mvp-frontend-$TARGET_STACK mvp-backend-$TARGET_STACK
+            mvp-ocr mvp-frontend-$TARGET_STACK mvp-backend-$TARGET_STACK
 
       - name: Wait for stack initialization
         run: sleep 10