Remove the smoke utility and the leftover demo application

[sassi67]

Summary

Final cleanup of the scaffolding inherited from the ModernCpp template, leaving only the code that serves the IIS module.

• Removed smoke.h/smoke.cpp and smoke_test.cpp — placeholder code with no relation to the module. This empties src/utils/, and a CMake target with zero sources is a hard error, so the IISNativeModuleUtils target goes with them.
• Removed src/main.cpp and the IISNativeModuleApp target — see the evaluation below. src/CMakeLists.txt is now a pure aggregator for core and module.
• Test target simplified — drops the IISNativeModuleUtils link and its explicit ../src include directory; the <core/...> includes resolve through the PUBLIC include directory IISNativeModuleCore already exports.
• CLAUDE.md updated to match: no app/utils targets, and the single-test example now names a TestCore case instead of the deleted smoke test.

Why src/main.cpp was safe to remove

It could not have survived the smoke removal regardless — its entire body was fmt::printing the smoke greeting. Everything else pointed the same way:

• The IISNativeModuleApp target it backed was linked by nothing.
• It is named nowhere in CI, which just builds everything and runs ctest.
• It is absent from scripts/generate_coverage.bat, which only uses the test binary.
• It is conceptually meaningless here: the deliverable is a DLL that IIS loads in-process, so a standalone main() has no role.

Note for reviewers

fmt and spdlog are intentionally kept in vcpkg.json and the top-level find_package calls even though no target links them any more — they stay available for future logging/formatting work. CLAUDE.md records this so they aren't later pruned as "unused".

Test plan

Verified from a wiped _build/:

• cmake --preset windows-x86-64-debug configures cleanly from scratch
• Full build: 3 targets (down from 5), no errors, no warnings
• All tests pass (2 TestCore cases; the smoke test is gone as intended)
• dumpbin -exports confirms the DLL still exports RegisterModule undecorated

🤖 Generated with Claude Code