The fix wave (4e1f545) put research + pdf in the prober's registry per
the owner ruling, but the doctrine never mentioned them. Owner chose
(2026-09-22) a brief grounded mention over schema-only discovery: the
paragraph extending 'read his actual material' now covers pdf (same
grounding for his PDF material, no copy-pasting) and research
(sparingly, only when pinning a fact would genuinely sharpen a probe
question — probing is measurement, not exploration, and a research
brief is never a reason to stall the questions).