lib: banner purge + WHY-only comment sweep (rule 8)

Every // ---- section banner dies (132 -> 0): names carry the WHAT.
Narration deleted (filename restatements, run-with lines, what-the-
next-line-does); every ref/hare cite, task cite, divergence, ABI/
layout contract, and ownership qualifier kept (borrowed-view lines
restored where the sweep over-cut). Comment-only proven: all 442
walk-workdir .s and 32 import-probe .s byte-identical before/after;
libbyteid 56-roster all-ID.

lib/io/types.ww

@@ -1,14 +1,8 @@
-// types — error union, mode/whence enums, reader/writer/closer
-// fn-type aliases. Project #94 fold-eFinal; the fn-aliases target
-// `stream` (= `*vtable`, the single io surface).
-//
 // Hare splits the io module across stream.ha + types.ha and ww does
-// the same: lib/io/io.ww owns the `eof` and `underread` tags;
-// lib/io/stream.ww owns the vtable surface (`vtable`, `stream`,
-// `read`/`write`/`close` dispatch); this file owns the surrounding
-// port. The four files share `package io;` so cross-file refs
-// resolve via the dir-enum concat order (io.ww < stream.ww < types.ww
-// — `stream` lands before the reader/writer/closer aliases below).
+// the same (#94 fold-eFinal). The four files share `package io;` so
+// cross-file refs resolve via the dir-enum concat order (io.ww <
+// stream.ww < types.ww — `stream` lands before the reader/writer/
+// closer aliases below).
 //
 // Deferrals (drew-signed): `copier`, `strerror` (the #5 list's
 // `handle` + `seeker` landed with the #5 arc and the memio-seeker