chore: add intermediate build artifacts to .gitignore

Add patterns for ccomptime intermediate files generated during compilation:
- .cc-runner-defs.c - runner definitions
- .cc-runner-main.c - runner main code
- .cct-final.c - final processed source
- .cct-runner - runner executable
- .comptime_safe.c - comptime-safe version of source

These are build artifacts that should not be tracked.

Author: claude

.gitignore

@@ -7,4 +7,9 @@ tests/**/out
 *.dSYM
 test
 tests/**/*.c.h
+tests/**/*.cc-runner-defs.c
+tests/**/*.cc-runner-main.c
+tests/**/*.cct-final.c
+tests/**/*.cct-runner
+tests/**/*.comptime_safe.c
 .DS_Store