Context Cache Construction

run_cmd and Git repo-root results memoized without the Provider Cache Server

Within a single command, repeated run_cmd(...) calls and repeated Git repo-root lookups across units used to share their cached results only when the Provider Cache Server was running. Commands invoked without --provider-cache (the common case for find, list, and run --all against estates that do not need provider caching) re-evaluated each run_cmd and re-shelled to git rev-parse --show-toplevel for every unit.

Both caches are now active for every command, so identical run_cmd arguments and repeated repo-root lookups are reused across units regardless of whether the Provider Cache Server is enabled.