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fix(probe-chain): refuse to report signal the tap was not actually measuring · 872676a2
The tool invented signal, and the invented signal sent an entire investigation down the wrong road. A run on 2026-07-28 came back with five different orbits at an IDENTICAL +0.0 dBFS peak. Twelve independent orbits do not peak at exactly full scale together — that was one shared source (the mix) being measured five times, because the capture nodes had acquired PipeWire links nobody asked for. `--target 0` is supposed to stop pw-record auto-connecting to the default source, and usually does, but not reliably. The consequence was worse than a missing number. The contaminated table said d4 and d5 had "recovered after seeding", so that got reported as a result, while Ardour's own meters showed no input on those tracks at all. PLN was looking at the truth and being told otherwise. A measurement tool that fabricates signal is not a tool — it is a confident liar, and it outranks the human's ears in an argument it should always lose. Two changes: * link() now CUTS every pre-existing link into the capture node before making its own, so an auto-connection cannot ride along. * verify() re-reads the graph AFTER the capture window and asserts the node was fed by exactly the two ports we intended. Checked after, not before, because an auto-connection can appear at any point while the node is alive — a setup -time check would still let contamination through. Rows that fail verification print "UNRELIABLE — ignore this row" INSTEAD of a diagnosis, plus a summary naming what each bad tap was really linked to. Refusing to answer is the correct behaviour here; a plausible wrong number costs hours. Validated by re-running against the live rig: the clean table (d1/d2/d3/d7 with signal, d4/d5/d9-d12 silent at source) matched what PLN could hear, where the contaminated one had contradicted him. Confirmed on the way that the SC->Ardour link mapping is exact (out_(2N-1)/out_(2N) -> ardour:Tidal NN for all 12), so the disagreement was never routing.PLN (Algolia) authored872676a2
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