Clean up old binary versions after download

[Catnap7]

Summary

Fixes #3028 by cleaning up stale downloaded binary version folders after a binary version is resolved.

This change:

• removes older version directories from the binary download folder after the current version is downloaded or already present
• keeps the selected versions for all managers that share the same binary folder, so shared Tari suite binaries are not removed prematurely
• ignores non-version sibling directories and files such as caches/checksums
• logs cleanup failures without failing the download/startup path, so a locked old file does not break recovery
• adds focused unit coverage for retained shared versions, non-version siblings, and missing parent folders

Verification

• git diff --check

I could not run cargo fmt --check or cargo test cleanup_old_binary_versions --lib in this Windows environment because cargo/rustc are not installed on PATH here.

[gemini-code-assist]

Code Review

This pull request introduces a cleanup mechanism for old binary versions within the binaries_manager.rs file. It adds a new function, cleanup_old_binary_versions, which iterates through the binary directory and removes any subdirectories that do not match the current version, accompanied by relevant unit tests. The reviewer suggested improving the robustness of this cleanup logic by ensuring the process continues even if an individual directory removal fails, rather than exiting early on the first error.

[gemini-code-assist]

The current implementation of cleanup_old_binary_versions stops immediately if it fails to read a directory entry or remove a specific folder (due to the ? operator). This means that if one old version directory is locked or inaccessible (common on Windows), other potentially removable old versions will be left behind. It is more robust to log the error for the failing entry and continue the loop to ensure as much cleanup as possible is performed.

    for entry in std::fs::read_dir(binary_folder)? {
        let Ok(entry) = entry else { continue };
        let path = entry.path();

        if !path.is_dir() || entry.file_name().to_string_lossy() == current_version {
            continue;
        }

        match std::fs::remove_dir_all(&path) {
            Ok(_) => {
                info!(
                    target: LOG_TARGET_APP_LOGIC,
                    "Removed old binary version folder: {}",
                    path.display()
                );
                removed_paths.push(path);
            }
            Err(error) => {
                warn!(
                    target: LOG_TARGET_APP_LOGIC,
                    "Failed to remove old binary version folder {}: {error:?}",
                    path.display()
                );
            }
        }
    }

[Catnap7]

Addressed in 1dbce200: remove_dir_all failures are now logged and skipped so cleanup continues with later old version folders. Entry and file-type read failures were already handled the same way.

git diff --check passes locally; Rust tests still cannot run in this Windows environment because cargo is not installed on PATH.