fix(node): index, serve and write files past Windows' MAX_PATHHEADmain

With the system's default setting (LongPathsEnabled off) every call given
a plain path of 260 characters or more refuses it, so a deep library was
partly invisible: the walk could not list such a directory and its files
never reached the members.

The node now hands each call that touches a group's disk the extended
form (paths.long_path), and keeps the plain path in the index, the hash
cache and the log. A directory is listed under its long form and its
entries named from the plain one (indexer.walk_files, wire._walk_dirs).
Covered: the walk, stats and hashing, reconcile and the watcher, the
folder list members see, serving over WebRTC and QUIC, deletion, uploads
and their recovery, folder creation and removal, audio tags and the
cover beside a track, photos, and a show's episode numbering. ffmpeg
extends a long path itself and keeps the plain one.

long_path now normalises before prefixing (the extended form skips the
system's normalisation) and starts at 248 characters, where creating a
directory is already refused.

test_long_paths.py runs with the setting off: 15 of its 17 tests fail
without the change. Checked by hand in the installed app with files at
312 to 380 characters.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 11 insertions, 7 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/indexer/enrich_audio.py b/packages/meshbay-node/src/meshbay_node/indexer/enrich_audio.py
index 397f760..ecc3b5e 100644
--- a/packages/meshbay-node/src/meshbay_node/indexer/enrich_audio.py
+++ b/packages/meshbay-node/src/meshbay_node/indexer/enrich_audio.py
@@ -60,11 +60,13 @@ image-file fallback for cover art, same as everything else.
 
 import asyncio
 import logging
+import os
 import re
 from collections.abc import Awaitable, Callable
 from pathlib import Path
 
 import blake3
+from meshbay_common.paths import long_path
 from meshbay_common.protocol import IndexEntry
 from mutagen import File as MutagenFile
 from mutagen.asf import ASF
@@ -155,8 +157,9 @@ _WMP_ALBUMART_GUID_RE = re.compile(r"^albumart_\{([0-9a-f-]{36})\}_(large|small)
 
 def _find_sibling_cover(folder: Path) -> Path | None:
     try:
-        candidates = [p for p in folder.iterdir()
-                     if p.is_file() and p.suffix.lower() in _COVER_EXTS]
+        with os.scandir(long_path(folder)) as listing:
+            candidates = [folder / e.name for e in listing
+                          if e.is_file() and Path(e.name).suffix.lower() in _COVER_EXTS]
     except OSError:
         return None
     if not candidates:
@@ -240,12 +243,12 @@ def _read_format_specific_tags(path: Path) -> tuple[dict, float | None] | None:
     suffix = path.suffix.lower()
     if suffix == ".wma":
         try:
-            return _asf_tags_from_object(ASF(str(path)))
+            return _asf_tags_from_object(ASF(long_path(path)))
         except Exception:
             return {}, None
     if suffix == ".mpc":
         try:
-            return _musepack_tags_from_object(Musepack(str(path)))
+            return _musepack_tags_from_object(Musepack(long_path(path)))
         except Exception:
             return {}, None
     return None
@@ -257,7 +260,7 @@ def _read_generic_tags_and_cover(
     tags: dict = {}
     duration: float | None = None
     try:
-        easy = MutagenFile(str(path), easy=True)
+        easy = MutagenFile(long_path(path), easy=True)
     except Exception:
         easy = None
     if easy is not None:
@@ -277,7 +280,7 @@ def _read_generic_tags_and_cover(
     cover: bytes | None = None
     if not skip_cover:
         try:
-            raw = MutagenFile(str(path))
+            raw = MutagenFile(long_path(path))
         except Exception:
             raw = None
         if raw is not None:
@@ -339,7 +342,8 @@ def _read_sibling_cover(path: Path) -> bytes | None:
     if sibling is None:
         return None
     try:
-        return sibling.read_bytes()
+        with open(long_path(sibling), "rb") as f:
+            return f.read()
     except OSError:
         return None