feat: support reading secret from stdin on set

feat: add `rm` and `del` aliases to `bioenv remove` command

build: add download-release install target

fix(store): handle export prefixes with tabs

refactor(config): extract sync value parsing

fix(cli): validate secret keys consistently

test(keychain): opt in keychain integration tests

chore(tamtam): ignore cache directory

feat(cli): accept yes/no sync aliases

refactor(keychain): inject security client