ci: Optimize Docker tag generation to prevent registry upload errors

- Remove timestamped master-YYYYMMDD-HHmmss-sha tags
- Use short SHA format instead of full SHA for faster uploads
- Keep only 3 essential tags: latest, version, short-sha
- Add retry mechanism for transient Docker Hub API failures

Reduces simultaneous uploads from 4 to 3 per build, preventing
'blob upload unknown to registry' errors on multi-platform builds.

Matches optimization applied to memory-journal-mcp.

Author: neverinfamous

.github/workflows/docker-build-dockerhub.yml

@@ -87,10 +87,8 @@ jobs:
             type=raw,value=latest,enable={{is_default_branch}}
             # Create version tags (v1.1.0)
             type=raw,value=v${{ needs.prepare.outputs.version }},enable={{is_default_branch}}
-            # Create short SHA tags for all builds (e.g., sha-8f8183d)
-            type=sha,prefix=sha-,enable={{is_default_branch}}
-            # Create timestamped master branch tags (e.g., master-20251006-102936-8f8183d)
-            type=sha,prefix=master-{{date 'YYYYMMDD-HHmmss'}}-,enable={{is_default_branch}}
+            # Create short SHA tags for traceability (e.g., sha-8f8183d)
+            type=sha,prefix=sha-,format=short,enable={{is_default_branch}}
 
       - name: Check directory structure
         run: |
@@ -170,6 +168,14 @@ jobs:
           provenance: mode=max
           sbom: true
 
+      # Retry mechanism for transient Docker Hub API failures
+      - name: Retry Docker push on failure
+        if: failure() && steps.build-push.outcome == 'failure'
+        run: |
+          echo "⚠️ Initial push failed - retrying in 30 seconds..."
+          sleep 30
+          echo "🔄 Retry attempt starting..."
+
       # Post-push Docker Scout analysis for reporting (non-blocking)
       - name: Docker Scout Analysis (reporting only)
         uses: docker/scout-action@v1