ww: separate package identity from declared name

lib/os/os.ww

@@ -4,12 +4,9 @@
 package os;
 
 import time;
-// [[args]] allocates the []str view via the `alloc` builtin, whose malloc
-// lowers to rt_malloc only when the rt binding is in the bundle (mirror
-// lib/strings/strings.ww:30 — every alloc-using module imports rt). os is
-// bundled by ~every program, so without this a plain `ww build` of any
-// os-importing program links bare libc `malloc` (undefined). Task #17.
-import rt;
+// [[args]] allocates the []str view via the `alloc` builtin. Package-mode
+// lowering targets the runtime ABI directly; no source import is needed merely
+// to trigger a linker choice, so the dependency graph remains source-semantic.
 
 @symbol("rt_syscall") fn syscall0(num: nr) i64;
 @symbol("rt_syscall") fn syscall1(num: nr, a: i64) i64;

lib/os/os_test.ww

@@ -20,7 +20,6 @@
 package os_test;
 
 import os;
-import rt;
 import test;