v0.16.3-pre

v0.16.3-pre

What changed

• Bundle the RDNA2-specific amdxc64.dll required by the pre10 test path
• Make variant INI overrides section-aware so missing keys are inserted into the correct sections
• Apply the RDNA2 pre10 overrides correctly:
  • [FSR] Fsr4ForceModel=2
  • [Plugins] LoadCustomAmdxc64OnRdna2=true