Add .clang-tidy and other quality improvements

.clang-tidy

@@ -0,0 +1,66 @@
+Checks: >
+  -*,
+  bugprone-*,
+  cppcoreguidelines-*,
+  modernize-*,
+  performance-*,
+  readability-*,
+  -bugprone-easily-swappable-parameters,
+  -bugprone-macro-parentheses,
+  -bugprone-reserved-identifier,
+  -cppcoreguidelines-avoid-c-arrays,
+  -cppcoreguidelines-avoid-magic-numbers,
+  -cppcoreguidelines-avoid-non-const-global-variables,
+  -cppcoreguidelines-macro-usage,
+  -cppcoreguidelines-no-malloc,
+  -cppcoreguidelines-owning-memory,
+  -cppcoreguidelines-pro-bounds-pointer-arithmetic,
+  -cppcoreguidelines-pro-type-cstyle-cast,
+  -cppcoreguidelines-pro-type-member-init,
+  -cppcoreguidelines-pro-type-reinterpret-cast,
+  -cppcoreguidelines-pro-type-union-access,
+  -cppcoreguidelines-pro-type-vararg,
+  -cppcoreguidelines-special-member-functions,
+  -cppcoreguidelines-use-enum-class,
+  -modernize-avoid-c-arrays,
+  -modernize-avoid-c-style-cast,
+  -modernize-concat-nested-namespaces,
+  -modernize-deprecated-headers,
+  -modernize-return-braced-init-list,
+  -modernize-use-auto,
+  -modernize-use-equals-default,
+  -modernize-use-nodiscard,
+  -modernize-use-nullptr,
+  -modernize-use-trailing-return-type,
+  -modernize-use-using,
+  -performance-enum-size,
+  -performance-no-int-to-ptr,
+  -readability-avoid-nested-conditional-operator,
+  -readability-convert-member-functions-to-static,
+  -readability-delete-null-pointer,
+  -readability-else-after-return,
+  -readability-identifier-length,
+  -readability-identifier-naming,
+  -readability-implicit-bool-conversion,
+  -readability-magic-numbers,
+  -readability-named-parameter,
+  -readability-uppercase-literal-suffix,
+  -readability-use-concise-preprocessor-directives,
+
+# Treat warnings as errors for these critical checks
+WarningsAsErrors: >
+  bugprone-unused-return-value,
+  performance-move-const-arg,
+  performance-unnecessary-copy-initialization,
+
+CheckOptions:
+  # Enforce [[nodiscard]] on functions returning non-void
+  - key: modernize-use-nodiscard.ReplacementString
+    value: '[[nodiscard]]'
+
+  # Performance tuning
+  - key: performance-unnecessary-value-param.AllowedTypes
+    value: 'ptr;AttributeID'
+
+FormatStyle: file
+...