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, 5 insertions, 2 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/ops/files.py b/packages/meshbay-node/src/meshbay_node/ops/files.py
index 4609627..a448103 100644
--- a/packages/meshbay-node/src/meshbay_node/ops/files.py
+++ b/packages/meshbay-node/src/meshbay_node/ops/files.py
@@ -4,8 +4,11 @@ from __future__ import annotations
 
 import asyncio
 import logging
+import os
 from pathlib import Path
 
+from meshbay_common.paths import long_path
+
 from meshbay_node.ops.core import OpError, _group_ctx
 
 log = logging.getLogger("meshbay_node.ops")
@@ -41,7 +44,7 @@ async def delete_file(state: dict, group_id: str, file_id: str) -> dict:
             f"not readable right now — the file is frozen, not gone", status=409)
 
     try:
-        path.unlink()
+        os.unlink(long_path(path))
     except FileNotFoundError:
         # Already gone from disk; drop the stale entry rather than refusing.
         log.warning("Index named a file that is not on disk: %s", path)
@@ -104,7 +107,7 @@ async def prune_index_cache(state: dict) -> dict:
             return True
         if any(not r.available for r in owning):
             return False
-        return not path.exists()
+        return not os.path.exists(long_path(path))
 
     paths = await cache.all_paths()
     stale = await asyncio.to_thread(lambda: [p for p in paths if _is_stale(p)])