refactor: libc - share printf, split the float path, fix relink deps

.gitignore

@@ -16,6 +16,8 @@ programs/obj/
 programs/src/*/obj/
 programs/libs/*/obj/
 programs/lib/libc/liblibc.a
+programs/lib/libc/liblibc-full.a
+programs/lib/libc/obj/libc-merged.o
 programs/lib/libloader/liblibloader.a
 programs/gui/icons/
 CLAUDE.md