Remove Gallus_Pub project and all related files

This commit deletes the entire `Gallus_Pub` directory, including its configuration, source files, and dependencies.

.vscode/extensions.json

@@ -0,0 +1,4 @@
+{
+  "recommendations": ["astro-build.astro-vscode"],
+  "unwantedRecommendations": []
+}