* fix: cache paths follow HYPERFRAMES_CACHE_DIR
Every place HyperFrames keeps downloaded or built files now takes its
folder from one helper, hyperframesCacheDir() in @hyperframes/core. The
default stays ~/.cache/hyperframes; HYPERFRAMES_CACHE_DIR moves it.
* fix: register the cache-dir subpath for bun and node, and build inspector from core source
* test: the cache-dir override test uses a folder that is absolute on every platform
* fix: the opencv cache follows HYPERFRAMES_CACHE_DIR
* fix(cli): npm installs run in their staging dir, so no cache path reaches a command line
* fix(cli): whisper.cpp is cloned inside its build dir, so no cache path is a git argument
* test(cli): the whisper clone test finds no system whisper on Windows either