Room Temperature, On Trial: The Hydride Ledger, Audited

An audit of a decade of high-pressure hydride superconductivity claims, checked line by line against the documents of record. Two receipts stand: H3S at 203 K under about 155 GPa (Drozdov et al., Nature, 2015) and LaH10 at about 250 K under about 170 GPa (Drozdov et al., Nature, 2019), independently reported above 260 K at 180-200 GPa by Somayazulu et al. (2019). Two room-temperature claims have fallen by retraction: carbonaceous sulfur hydride at 287.7 K and 267 GPa (Nature, 2020; retracted by the editors in 2022 over an undisclosed, non-standard background subtraction in the magnetic susceptibility data, all authors disagreeing) and nitrogen-doped lutetium hydride at 294 K and 10 kbar (Nature, March 2023; retracted in November 2023 at the request of eight of its eleven authors, with the journal separately finding concerns about the resistance data credible, substantial, and unresolved). The live dispute over the magnetic evidence for the standing receipts is priced fairly at both published strengths. No new physics is claimed; the audit is the result, and it prints the standard the episode teaches: which measurements, in which order, a future room-temperature claim must show before the field spends belief. Grade: AUDIT STANDS - RECEIPTS HELD, CLAIMS FALLEN, STANDARD PRINTED. This paper stands outside the corpus's vacuum ledger; it neither spends that ledger nor repairs it, and it touches no claim of that program.