fix(fmt): balance override variable indentation

[figtracer]

Fixes #15151.

Summary

• Balance the extra formatter box opened for state variables with an override attribute when the variable has no initializer.
• Add regression coverage for uninitialized override variables followed by top-level declarations, a following contract member, override path lists, and the initializer case that already worked.

Root Cause

print_var opens an additional box while printing override attributes. The initializer path closes that box before formatting the RHS, but the no-initializer path only closed the regular variable boxes. That left the pretty-printer one indent level deep, so later source-unit items were emitted indented.

[grandizzy]

lgtm!