QGIS Union Overlay Analysis Assistance

I have several vector layers that need to be run through a Union overlay in QGIS. The goal is to produce a single layer that accurately preserves every geometric intersection while carrying over the full set of source attributes.

Here’s what I need from you:
• A clean GeoPackage (or shapefile, if you prefer) containing the unioned layer with all attributes intact.
• A brief summary of the steps you took (screen captures or a short text file are fine) so I can replicate the workflow later.
• The QGIS project file set up so I can open it and see the final result immediately.

Please double-check that no geometries are lost, topology is valid, and attribute names remain unchanged. If you can have this ready quickly, even better—I’m on a tight turnaround.