Root unit: outputs landed in /tmp/tg-cache ✓

--download-dir is now respected through dependency blocks and read_terragrunt_config

A custom download directory set via --download-dir (or TG_DOWNLOAD_DIR) was honored for the unit being run, but lost as soon as parsing crossed into another config. dependency blocks and read_terragrunt_config() would fall back to the dependency's local .terragrunt-cache next to its terragrunt.hcl, ignoring the user-set path.

TG_DOWNLOAD_DIR=/tmp/tg-cache terragrunt run --all plan
# Root unit: outputs landed in /tmp/tg-cache ✓
# Dependency outputs: written next to each dependency's terragrunt.hcl ✗

When the parsing context switches to a new config path, the download directory is now updated only if it still points at the previous module's default location. A user-supplied path never matches any module's default and is carried through every dependency hop unchanged.

Thanks to @maonat for contributing this fix!