The walk now drains its frontier, prefetches the wave's registry
archives with a small thread pool (deduped by URL, progress bars
suppressed per thread since parallel bars would interleave), and then
processes the wave sequentially; the sequential download() call stays
authoritative so failures surface with resume exactly as before. Same
approach as the espidf tool prefetch in #18513.
Registry version and file entries that are not dicts now raise the same
Unexpected-response error as the other shape guards instead of an
AttributeError traceback. install_package rejects an empty expect so
every install is layout-validated before the marker is written.
ESPHOME_CCACHE_ENABLE values outside 1/true/yes/on and 0/false/no/off
warn and are treated as unset instead of bool(str) flipping them to
enabled. The strip_win_long_path_prefix test moved next to the function
in test_framework_helpers, and a stale comment naming its old module is
fixed.
J. Nick Koston