feat: /version endpoint; fix deploy action inputs

- Bake the commit SHA into the image (GIT_SHA build arg) and serve it at
  /version, so a deploy can be verified end to end. This repo is the
  dockerloid deploy test service.
- cssnr/portainer-stack-deploy-action@v1 reads `endpoint` and `pull`;
  `endpoint_id` / `pull_image` were silently ignored.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitea/workflows/deploy.yml

@@ -51,9 +51,11 @@ jobs:
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           platforms: linux/amd64
+          build-args: |
+            GIT_SHA=${{ github.sha }}
 
   deploy:
-    name: Deploy to Portainer
+    name: Deploy
     needs: [build]
     runs-on: docker
     container:
@@ -68,8 +70,8 @@ jobs:
           name: ${{ secrets.PORTAINER_STACK_NAME }}
           file: docker-compose.yml
           type: file
-          pull_image: true
-          endpoint_id: ${{ secrets.PORTAINER_ENDPOINT_ID }}
+          pull: true
+          endpoint: ${{ secrets.PORTAINER_ENDPOINT_ID }}
           env_data: |
             {
               "IMAGE": "${{ env.REGISTRY }}/${{ github.repository_owner }}/ascii-art-app:latest"