## Fix incorrect directory path folding in slash command file collection
**Description:**
This PR fixes a bug in the `collect_files` function where the directory
folding logic (used to compact chains like `.github/workflows`) failed
to reset its state when traversing out of a folded branch.
**The Issue:**
The `folded_directory_names` accumulator was persisting across loop
iterations. If the traversal moved from a folded directory (e.g.,
`.github/workflows`) to a sibling directory (e.g., `.zed`), the sibling
would incorrectly inherit the prefix of the previously folded path,
resulting in incorrect paths like `.github/.zed`.
**The Fix:**
* Introduced `folded_directory_path` to track the specific path
currently being folded.
* Added a check to reset `folded_directory_names` whenever the traversal
encounters an entry that is not a child of the currently folded path.
* Ensured state is cleared immediately after a folded directory is
rendered.
**Release Notes:**
- Fixed an issue where using slash commands to collect files would
sometimes display incorrect directory paths (e.g., showing
`.github/.zed` instead of `.zed`) when adjacent directories were
automatically folded.
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Co-authored-by: Lukas Wirth <lukas@zed.dev>