🚀 Major refactor: Reorganize project structure

- Move WebAPI/ → src/Backend/DiunaBI.WebAPI/
- Move Frontend/ → src/Frontend/
- Move Deployment/ → deploy/
- Add proper .NET 8 solution structure
- Add plugin architecture with DiunaBI.Plugins.Morska
- Clean

tools/sql-scripts/utlis/RemoveLayer.sql

@@ -0,0 +1,3 @@
+DECLARE @LayerId UNIQUEIDENTIFIER = '41e7377c-aa8c-4528-843d-dcc3fe13b412';
+DELETE FROM [diunabi-morska].[dbo].[Records] WHERE [LayerId] = @LayerId;
+DELETE FROM [diunabi-morska].[dbo].[Layers] WHERE [Id] = @LayerId;