chore(codeowners): expand 1-byte placeholder to real ownership rules (#516)

Co-authored-by: Forge <forge@kooshapari.com>

Author: KooshaPari

.github/CODEOWNERS

@@ -1 +1,10 @@
-* @Phenotype-Enterprise/engineering-leads
+# Global code owners for KooshaPari org
+* @KooshaPari
+
+# Infrastructure as code
+/iac/ @KooshaPari
+/.github/ @KooshaPari
+
+# Security-sensitive
+/SECURITY.md @KooshaPari
+/.github/dependabot.yml @KooshaPari