G-126 progress: directory-mtime restoration landed upstream (v2.3.1)

Upstream punkzip 0882f03 fixes the long-standing dir-mtime limitation
via a deferred post-extraction stamping pass (windows direct
CreateFileW BACKUP_SEMANTICS + SetFileTime; Io best-effort elsewhere),
pinned by tests at the stored epoch including the -d route and the
build roundtrip. Notes bullet updated from proven-fixable to fixed.

Assisted-by: harness=claude; primary-model=claude-fable-5; api-location=anthropic.com

goals/G-126-punkzip-accelerator.md

@@ -172,23 +172,24 @@ working tree; one now exists.
   synchronous and unaffected.
 
 - Timestamp behaviour on extraction, measured 2026-07-27 (info-zip fixture, stored DOS
-  time 2021-10-06 01:50:08): FILE mtimes are preserved exactly (epoch 1633485008,
-  identical between the current v2.3.0 exe and the old Nov-2024 v2.1.0 exe - no
-  regression through the 0.15/0.16 ports; the set-timestamps-before-write order does
-  not get stomped on Windows). File atimes and DIRECTORY mtimes are NOT preserved
-  (both read as extraction time; the dir case is the long-standing zig limitation the
-  extract output flags with "UNABLE TO SET MTIME ON FOLDER" - zig 0.16 Io still cannot
-  do it: read-only dir handles lack FILE_WRITE_ATTRIBUTES and write-mode dir opens
-  return error.IsDir). PROVEN FIXABLE in punkzip: direct
-  CreateFileW(FILE_FLAG_BACKUP_SEMANTICS, FILE_WRITE_ATTRIBUTES) + SetFileTime on the
-  directory works (verified read-back exact); a proper fix stamps directories in a
-  deferred pass AFTER their contents are extracted, since creating children updates
-  the parent's mtime. SEMANTICS NOTE for the parity suite: punkzip interprets the
-  zone-less DOS timestamp as UTC (deterministic, tz-free, and build->extract
-  roundtrips exactly); bsdtar instead honours Info-ZIP's UT extra field (true UTC),
-  so third-party comparisons can differ by the creator's tz offset (2h on this
-  fixture, made in UTC+2). Compare mtimes via the raw dostime or via punkzip's
-  UTC-interpretation convention, never via a local-time conversion.
+  time 2021-10-06 01:50:08): FILE mtimes preserved exactly (epoch 1633485008,
+  identical between the v2.3.x exes and the old Nov-2024 v2.1.0 exe - no regression
+  through the 0.15/0.16 ports; the set-timestamps-before-write order does not get
+  stomped on Windows). File atimes read as extraction time (cosmetic). DIRECTORY
+  mtimes were NOT preserved - the long-standing zig limitation ("UNABLE TO SET MTIME
+  ON FOLDER"; zig 0.16 Io still cannot do it: read-only dir handles lack
+  FILE_WRITE_ATTRIBUTES and write-mode dir opens return error.IsDir) - and this is
+  now FIXED in punkzip v2.3.1 (upstream 0882f03, user-directed): directory members
+  are stamped in a deferred pass AFTER their contents exist (child creation bumps the
+  parent's mtime), on windows via direct CreateFileW(FILE_FLAG_BACKUP_SEMANTICS,
+  FILE_WRITE_ATTRIBUTES) + SetFileTime, best-effort via Io elsewhere; pinned by tests
+  at the stored epoch, including through the -d joined-path route and the
+  build->extract roundtrip (DOS 2-second granularity). SEMANTICS NOTE for the parity
+  suite: punkzip interprets the zone-less DOS timestamp as UTC (deterministic,
+  tz-free, and build->extract roundtrips exactly); bsdtar instead honours Info-ZIP's
+  UT extra field (true UTC), so third-party comparisons can differ by the creator's
+  tz offset (2h on this fixture, made in UTC+2). Compare mtimes via the raw dostime
+  or via punkzip's UTC-interpretation convention, never via a local-time conversion.
 
 ## Progress
 
@@ -237,6 +238,10 @@ working tree; one now exists.
   directories - the scanner's file-vs-dir probe silently recorded directories as
   empty files until opens passed `.allow_directory = false` (guard also added to
   list/extract file opens).
+- 2026-07-27 directory-mtime restoration landed upstream (user-directed; commit
+  0882f03, punkzip v2.3.1, suite 130/130): extract now restores directory mtimes via
+  the deferred stamping pass described in Notes; the "(Making dir: ...)" output line
+  lost its UNABLE-TO-SET-MTIME suffix and the CLI tests pin the restored times.
 - Remaining for acceptance: vendor into `src/tools/punkzip/` with provenance
   (upstream commit id), re-vendor procedure and licence records; make.tcl tool build
   step (zig OPTIONAL - absence reported, not fatal; test gate keys on exit code, not