Module advise 

The headless design-deliberation stage between magi plan’s interview and the task file it files.

crate::graph’s judge / vote / deliberate machinery only runs when more than one candidate survives - and [graph] candidates defaults to 1 now (see crate::config::Graph::candidates’s doc for the cost numbers behind that default), so on an ordinary task none of that machinery ever fires any more. Diversity did not stop paying for itself; it moved. A design sketch is a few paragraphs an agent can write without touching the repository, where a full implementation is a hundred-plus-turn tool loop that re-reads the codebase on every turn - so three sketches, gathered once between the interview and the file, cost a fraction of a third implementation and buy back the same disagreement the judges used to surface, on every task rather than only the ones run with --candidates.

Three independent, read-only advisors ([gather]) each propose one design. The planner seat ([roles] planner) then reads all three and prompt::synthesizes them into the task file’s ## Context and ## Change, naming which advisor’s idea it kept where - it is told, in so many words, not to pick a winner. Nothing here talks to the operator: the interview already did that, and turning this stage into three more conversations would be exactly the cost this module exists to avoid.

Disposability narrows the blast radius, it does not forbid writing

allow_write: false alone is not a guarantee: opencode has no read-only mode at all, and Claude’s --disallowed-tools stops its edit tools but not a rm or a redirect run through its Bash tool. That is the existing, accepted risk model for every read-only seat in this codebase - judge and reviewer seats in crate::graph carry exactly the same weak guarantee, and get away with it because their cwd is already a worktree the run treats as disposable. This stage runs before any run exists, so it was pointed at the operator’s own checkout until [checkout_worktrees] gave every advisor seat, and the planner’s synthesis, a git worktree add --detach checkout at HEAD of their own, thrown away when run returns - the same protection judges and reviewers already had, closing the one gap unique to this stage rather than inventing a stronger guarantee nothing else here provides.

What this buys: a relative-path write from a seat that ignores its instructions lands in that seat’s own disposable checkout, not in the operator’s repository and not in another seat’s. What it does not buy: an absolute-path write, or an edit to the shared .git metadata a linked worktree does not copy (its own config extension aside), can still reach outside the checkout - the same as it always could for a judge or a reviewer. Closing that would mean sandboxing the process itself (a container, a chroot, an OS-level read-only mount), which no seat of any kind in this codebase has today; adding one is a different, much larger change than a design-deliberation stage, not something this module can give an advisor seat on its own.

The draft survives every failure short of success

run never writes to draft until it holds a complete, synthesized replacement. Every early return - an advisor roster that produced nothing usable, a planner seat that crashed or answered with no fenced task block - leaves the interview’s own draft exactly as the leader wrote it, and the error names its path, the same contract [crate::plan::vet] keeps for a validation failure. The raw advisor records are written to disk unconditionally, before that check even runs, so a total failure still leaves something for the operator to read.

Structs

Advice

The whole deliberation: one record per advisor seat, written to <id>.advisors.json next to the draft so the operator can read every seat’s reasoning - including a seat that failed - not only whichever parts synthesis kept.

AdvisorRecord

One advisor seat’s outcome, kept even on failure so a synthesis that only had two of three proposals to work with is not a mystery later - see run’s doc.

Functions

run

Run the design-deliberation stage: gather independent proposals, write the raw record, synthesize them under the planner seat, and overwrite draft with the result.