Function resolve_cached_kernel 

pub fn resolve_cached_kernel(
    id: &KernelId,
    cli_label: &str,
    mp: Option<&FetchProgress>,
) -> Result<PathBuf>

Resolve a Version or CacheKey identifier to a cache entry directory.

Lookup order: local cache, then the remote GHA cache when remote_cache::is_enabled() returns true. Miss behavior differs by variant:

• Version: major.minor prefixes (e.g. "6.14") resolve to the latest patch via crate::fetch::fetch_version_for_prefix first. On full miss, downloads the kernel from kernel.org, builds it, and stores it in the cache via download_and_cache_version.
• CacheKey: errors on miss — cache keys are content-hashes and not downloadable. The error hint suggests running {cli_label} kernel list.

cli_label is the human-facing command name ("ktstr" or "cargo ktstr") threaded into status output and error messages.