docs: scope CHANGELOG lock-path note to APFS; document expected_hashes exemption

Post-audit polish: the lock-path self-alias tolerance can never run on
native Windows (writes are refused earlier), so the CHANGELOG names APFS
only; the portability pre-pass comment records why probe-only
expected_hashes keys are exempt (read preconditions on legacy names must
stay expressible).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EAiQCkG4JfmgdqE563r3Az

Author: claude

CHANGELOG.md

@@ -24,10 +24,11 @@ implementation record for older releases.
   (previously `read_text` newline normalization made every chunk look stale).
 - Under a held mutation lock, a vault whose on-disk name differs only by case
   from the spelling used on the command line is no longer misreported as its
-  own portable alias on case-insensitive filesystems (APFS, NTFS); the
-  descriptor-pinned vault object is recognized as itself. Inspect-time
-  auditing keeps the stricter shipped behavior, since an absent init root on
-  a case-insensitive volume cannot distinguish itself from an alien sibling.
+  own portable alias on case-insensitive filesystems (APFS; the lock layer
+  never runs on native Windows); the descriptor-pinned vault object is
+  recognized as itself. Inspect-time auditing keeps the stricter shipped
+  behavior, since an absent init root on a case-insensitive volume cannot
+  distinguish itself from an alien sibling.
 
 ### Changed
 

claude_obsidian/transaction.py

@@ -3277,6 +3277,9 @@ def _prepare_writes(
     # Lexical portability pre-pass before any filesystem probe so unportable
     # plans are rejected with the same code on every platform (a Windows lstat
     # of e.g. "a:b.md" would otherwise fail first with a different error).
+    # expected_hashes keys are deliberately exempt: probe-only keys are read
+    # preconditions, and a legacy vault must stay able to pin the state of a
+    # pre-existing file whose historical name violates the portable rules.
     for raw in raw_writes:
         if isinstance(raw, dict) and isinstance(raw.get("path"), str):
             _assert_portable_write_path(raw["path"])