Use when generating thesis candidates for an AutoSurvey run, or when /survey-thesis is invoked. Reads brief.parsed.json + filtered.jsonl (top-30 by citation), proposes 2-3 contestable thesis candidates, generates a 1-2 page sample chapter PDF preview for each candidate, then waits for user selection. Writes 2_thesis/thesis.json. The thesis-first paradigm is the load-bearing innovation of AutoSurvey.
