fix: Docker publish workflow — BUILD_TIME and APP_VERSION build args

BUILD_TIME was passed as a literal $(date ...) string in the with: block,
which is not evaluated as a shell command. Moved to a preceding step that
writes to GITHUB_OUTPUT.

APP_VERSION used github.ref_name which resolves to 'master' on push events.
Now uses the tag name for tag pushes, or the commit SHA otherwise.

.github/workflows/deploy.yml

@@ -276,18 +276,6 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v5
 
-      - name: Pull GHCR edge image (or fall back to local build)
-        run: |
-          GHCR_IMAGE="ghcr.io/kpa-clawbot/corescope:edge"
-          echo "Attempting to pull $GHCR_IMAGE ..."
-          if docker pull "$GHCR_IMAGE" 2>/dev/null; then
-            # Tag as the local image name that docker-compose.staging.yml expects
-            docker tag "$GHCR_IMAGE" corescope-go:latest
-            echo "✅ Using pre-built GHCR edge image"
-          else
-            echo "⚠️ GHCR pull failed — using locally built image from build job"
-          fi
-
       - name: Deploy staging
         run: |
           # Stop old container and release memory

.github/workflows/publish.yml

@@ -39,6 +39,19 @@ jobs:
             # On master push: edge
             type=edge,branch=master
 
+      - name: Set build time
+        id: buildtime
+        run: echo "value=$(date -u +'%Y-%m-%dT%H:%M:%SZ')" >> "$GITHUB_OUTPUT"
+
+      - name: Compute app version
+        id: appversion
+        run: |
+          if [[ "${{ github.ref }}" == refs/tags/v* ]]; then
+            echo "value=${{ github.ref_name }}" >> "$GITHUB_OUTPUT"
+          else
+            echo "value=${{ github.sha }}" >> "$GITHUB_OUTPUT"
+          fi
+
       - uses: docker/build-push-action@v6
         with:
           context: .
@@ -47,8 +60,8 @@ jobs:
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           build-args: |
-            APP_VERSION=${{ github.ref_name }}
+            APP_VERSION=${{ steps.appversion.outputs.value }}
             GIT_COMMIT=${{ github.sha }}
-            BUILD_TIME=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
+            BUILD_TIME=${{ steps.buildtime.outputs.value }}
           cache-from: type=gha
           cache-to: type=gha,mode=max