comments: drop retired lint markers, re-cite migrated carriers

peel-ok/sizelint-ok/primsize-ok annotations lose their tools; sites
keep the WHY in plain words. Citations of retired carriers move to
their fixture or @test successors (949_errtype_compare -> r949_*,
900_stdlib -> library owners).

lib/regex/regex_whitebox.ww

@@ -10,12 +10,13 @@
 // the non-T @test drop, #6). Load-bearing ww-compiler coverage (drove
 // #34/#38/#44/#45/#48), not black-box-reachable.
 //
-// `_whitebox.ww` (NOT *_test.ww) keeps this file in the production
-// enumerator's root-package assembly until package-aware testing can classify
-// same-package `*_test.ww` files (T1). The T0 gate resolves `regex` as the root
-// directory so -T sees these tests directly; importing regex as a dependency
-// would strip them. Public-API tests remain a separate `package regex_test`
-// binary in lib/regex/regex_test.ww (CLAUDE.md rule 9).
+// This noncanonical `_whitebox.ww` name is retained during migration. The
+// package planner's explicit compatibility rule recognizes its line-leading
+// @test declarations and assembles it with the production `regex` sources;
+// ordinary production files merely ending in `test.ww` stay production.
+// Importing regex as a dependency still strips these tests. Public-API tests
+// remain a separate `package regex_test` binary in lib/regex/regex_test.ww
+// (CLAUDE.md rule 9).
 package regex;
 
 import io;