Authorize a Third Round on the #1635 Token-Fallback Fix, or Drop It #1844

The fix for #1635 on branch feature/auto-1635 (handoff #1835) used up its two-round local-review budget. An introduced finding is still open, so editing stopped, per local-strict-review "Disposing of Findings". No pull request exists yet. The branch is pushed.

Where it stands

• _operator_tokens in host-setup/agent-safety/claude/gh-write-guard.py handles a line that fails to parse. It retries the line without the trailing comment bash sees, then falls back to plain splitting as the develop base does. _strip_trailing_comment finds that comment and tracks only plain ' and ".
• It fixes An Apostrophe in a # Comment Defeats Requirement 7 Entirely #1635: while ! gh pr checks 5 --watch; do sleep 30; done # the PR's checks is now denied. The round-1 regressions are fixed too. A differential against the develop base shows no deny-to-allow change over the self-test corpus.
• Still open (introduced): the comment scan runs one line at a time, and each line starts outside any quote. Bash can start a line inside a quote an earlier line opened. In that case a # inside the quote gets cut as a comment, and the command after the quote closes is dropped. Constructed reproductions that develop denies and the branch allows:
  • A three-line command. Line 1 opens a double quote (echo "start). Line 2 closes it after a # and then runs a cross-owner gh issue comment write. Line 3 ends in a comment with an apostrophe.
  • A four-line command, echo "a / <<EOF # " / while true; do sleep 5; done / EOF. No apostrophe is needed, because _heredoc_opener tokenizes one line at a time.

Options

1. Recommended: authorize a third round with the root-cause fix. Carry the quote state across lines: strip comments over the whole command before the whole-command parse, not per line. Keep _heredoc_opener on base behaviour, with no comment stripping. Why: the defect is structural, the fix is narrow and known, and the reviewer found the single-line scan sound. What happens to the parked work: the branch continues, another review pass runs, and the pull request is driven to develop.
2. Drop comment stripping and fall back to base. Why: it removes the regression with certainty. The cost is that An Apostrophe in a # Comment Defeats Requirement 7 Entirely #1635 is not fixed. What happens to the parked work: the branch is discarded, and An Apostrophe in a # Comment Defeats Requirement 7 Entirely #1635 goes back to the backlog for a redesign, for example a tokenizer that follows bash's quoting across lines.

Blocks: the feature/auto-1635 branch, which has no pull request yet. Handoff: #1835.