clang-tidy: Initial commit

Added initial .clang-tidy configuration file with recommended C++ checks
aligned with the OpenBMC-approved checklist. This setup enforces modern
C++ best practices and helps catch common issues early in development.

Tested: verified build.

Change-Id: I5a0d4e74dd27c1dec449c2bb7071dbf9ffe1ab0a
Signed-off-by: Jayanth Othayoth <ojayanth@gmail.com>
diff --git a/.clang-tidy b/.clang-tidy
new file mode 100644
index 0000000..8b0c596
--- /dev/null
+++ b/.clang-tidy
@@ -0,0 +1,8 @@
+Checks: '-*,
+    bugprone-unchecked-optional-access,
+    modernize-use-nullptr
+    '
+
+HeaderFilterRegex: (?!^subprojects).*
+
+WarningsAsErrors: '*'