Lock file creation fails when path is a file (Not a directory error)

[yaoduan]

Bug Description

When attempting to reindex a file (e.g., `viking://user/wangyd/memories/profile.md`), the lock acquisition fails with error:

```
[POINT] Failed to create lock file: plugin error: failed to open file: Not a directory (os error 20)
```

Root Cause

In `openviking/storage/transaction/path_lock.py:67`:

```python
def _get_lock_path(self, path: str) -> str:
path = path.rstrip("/")
return f"{path}/{LOCK_FILE_NAME}" # LOCK_FILE_NAME = ".path.ovlock"
```

This generates lock path `/local/default/user/wangyd/memories/profile.md/.path.ovlock` for a file path, but `profile.md` is a file, not a directory. Creating a file under a file path causes "Not a directory" OS error.

Expected Behavior

For file paths, the lock file should be placed in the parent directory or use a different naming scheme.

Environment

• OpenViking version: 0.3.14
• Platform: macOS (darwin)
• Python: 3.14

Steps to Reproduce

1. Start OpenViking server
2. Run `ov reindex 'viking://user/wangyd/memories/profile.md' --wait`
3. Observe error: `LockAcquisitionError: Failed to acquire point lock for ['/local/default/user/wangyd/memories/profile.md']`

Suggested Fix

Modify `_get_lock_path` to detect if path is a file and place lock file in parent directory (e.g., `/path/to/.file.md.ovlock`).

[qin-ctx]

Thanks for reporting this, and welcome to your first OpenViking issue report!

I confirmed that this is still present in the current code. The maintenance reindex path converts the URI directly to an AGFS path and then enters LockContext(..., [path], lock_mode="point") in openviking/server/routers/maintenance.py:105-112. PathLock._get_lock_path() always maps a locked path to {path}/.path.ovlock in openviking/storage/transaction/path_lock.py:65-67, and acquire_point() later writes that lock file in openviking/storage/transaction/path_lock.py:236-270.

That means a file URI such as viking://user/wangyd/memories/profile.md becomes a file path, and the lock layer tries to create profile.md/.path.ovlock. Depending on the AGFS backend, this can surface as Not a directory or another file-under-file creation error.

The fix should probably not change the global lock-file naming rule in PathLock. Existing callers such as VikingFS.rm() already handle this by checking the target type first: directories lock the target path, while files lock the parent directory (openviking/storage/viking_fs.py:437-465). Reindex should follow the same file-vs-directory split:

• directory URI: keep locking the directory path and run the existing directory reindex flow;
• file URI: lock the parent directory instead of the file path;
• also define the single-file reindex behavior explicitly. Today index_resource() is directory-oriented: it reads directory metadata and lists uri for files under it (openviking/utils/embedding_utils.py:431-492). If ov reindex viking://.../profile.md is meant to be supported, that path should directly vectorize the file; otherwise it should return a clear unsupported-file-reindex error.

If you are interested in contributing a fix, we would be happy to provide guidance.