Researches the change — always maps the codebase status quo; spawns a web-survey researcher agent ONLY when the decision space is external (new dependency / tech choice / unfamiliar domain), never for internal refactors or fix batches. Findings go into research.md (single file; Open[TBD]/Decided maintained as before). Changing direction = snapshot the current research.md into the research/ discarded-draft pile first, then overwrite; old drafts can be resurrected at any time.
