fix: auto-build Docker image on tag push (closes #547)

Trigger Docker build workflow only when a new version tag (v*) is
pushed, instead of waiting for a GitHub Release to be published.
This removes the manual release step and keeps CI usage minimal.

Made-with: Cursor

.github/workflows/docker-publish.yml

@@ -1,8 +1,9 @@
 name: Build and Push Docker Image
 
 on:
-  release:
-    types: [published]
+  push:
+    tags:
+      - "v*"
   workflow_dispatch:
 
 env: