[Bug]: [Document Reporting] Theme docDefaults is lost during layout merge, so the theme's body size never applies

Describe the issue

The merge that combines header/footer, body and theme into a finished Word layout does not carry w:docDefaults from the theme. Since the theme declares its body font size only in docDefaults, the size is silently dropped and the output falls back to whichever base document's docDefaults survives.

Worse than a no-op: applying the theme can make the result less correct than not applying it. The theme's Normal style carries no w:sz at all — it relies on docDefaults. When it overwrites a header/footer Normal that does carry an explicit size, the explicit size is removed and the paragraph falls to the wrong base.

Expected behavior

A layout built with a given theme renders body text at that theme's declared size. Changing doc_defaults.size_pt in the theme and rebuilding changes the output.

Steps to reproduce

Take one theme and wrong with body layout see header footer is wrong - take the corrected theme and see now it is working. The font styles are wrong on the one with the wrong themes

Additional context

Default Theme with DocumentDef (not working)
Defauult Theme where we have move this to each style (works with merge)