Three changes from automated review on PR #376:
1. Add `--` option terminator before host in _wrap_ytdlp_cmd (P1 security)
Prevents SSH option injection if LAST30DAYS_YT_SSH_HOST were ever set
to a value starting with `-` (e.g. `-oProxyCommand=...`). Low
exploitability since the env var is user-controlled config — but the
fix is a single arg and turns a self-harm footgun into no footgun.
2. Hoist `import shlex` to module-level (P2 style)
Pure stdlib import, no reason for the deferred form. Cleaner.
3. Cache _ytdlp_ssh_host() result in fetch_transcript (P2 style)
Was being called 2-3x per video; the function is cheap (env lookup
+ strip) so this is purely about readability.
Adds test_wrap_cmd_uses_option_terminator covering the security fix
explicitly with a `-oFoo=bar` host value. Updates index assertions in
the two existing tests that check command shape (host is now at index
4, command string at 5, with `--` at 3).
shoobee
f4eb0af104