Because DllInjector enforces matching host/target bitness, a 32-bit caller
always handles a 32-bit target. The correct API is native
GetThreadContext/SetThreadContext with Context32; the Wow64 APIs are only for
64-bit processes inspecting WOW64 targets, which never happens here.
- Collapse the 32-bit path to always use GetThreadContext/SetThreadContext.
- Remove the now-unused Wow64GetThreadContext/Wow64SetThreadContext
declarations.
- Update Context32 doc comment to describe the x86 usage.
- ExternalReader access guard now also accepts QueryLimitedInformation.
Tests: 207 passing, 4 skipped.