fix: name the exact flags required when not a TTY

We already refuse destructive actions without `--yes` off-TTY (`confirmation_required`). Other interactive paths (`docs ask` chat, `config` editor, any future prompt) should fail the same way: list the flags that replace the prompt.

Agents copy flag names out of the error. A prompt with no TTY is a dead end.

Audit current prompts. Each one gets a non-TTY error that names flags. No new prompts that lack a flag equivalent.

Acceptance: running the chat/editor path with stdin not a TTY exits non-zero and names the flags. Tested without a TTY.

Start by locating the existing `confirmation_required` handling and audit the prompt entry points for `docs ask` chat and the `config` editor. Run each path with stdin not attached to a TTY, then verify it exits non-zero and names the flags that replace the prompt; future prompts should follow the same rule.

Written by the indexing model from the issue text.