Disable misc-include-cleaner

[helly25]

Fourth clang-tidy triage PR. .clang-tidy only, clearing the largest remaining check: 69 findings across 30 files.

Why

The check demands a direct include for every symbol used, which fights this codebase's umbrella headers.

mbo/types/stringify_test.cc includes exactly one project header, mbo/types/stringify.h, and then uses the concepts that header exists to expose:

using ::mbo::types::types_internal::kStructNameSupport;
using ::mbo::types::types_internal::SupportsFieldNames;
using ::mbo::types::types_internal::SupportsFieldNamesConstexpr;

The check asks it to include mbo/types/internal/struct_names.h directly instead. Satisfying that would have tests reaching past the public header into an internal one — deepening precisely the coupling the umbrella header was written to avoid. Same shape in json_test.cc (mbo::types::ThreeWayComparableTo, which lives in traits.h).

On the concepts issue

The check is also reported to mishandle concepts, with uses inside requires clauses going unattributed. I have recorded that in .clang-tidy as a known issue rather than something reproduced here — every finding I inspected was a genuine "no direct include" report, including traits_test.cc being flagged for std::same_as when it really does not include <concepts>.

So the umbrella-header conflict is the operative reason, and the rationale in the config says so rather than overclaiming a tool bug. If include hygiene is wanted later, IWYU proper is the better tool for it.

Test

• The check reports zero on previously affected files (stringify.cc, json_test.cc, demangle.cc).
• The other 26 misc-* checks stay enabled — this disables one check, not the group.
• clang-tidy --verify-config clean, so the name is not a typo silently doing nothing.
• pre-commit run -a green.