The Geometric Arrow of Measurement: A Synthesis of the Incidence–Rigidity Programme — the Third Verdict, its Enclosure, and a First Record Witness

This synthesis condenses a multi-phase research programme on the geometric origin of the measurement arrow: whether the registered temporal orientation of a quantum measurement is irreducibly geometric or reducible to an effective (CPTP) channel. The question is converted into a theorem of empirical non-equivalence and computed where it can be decided — on a genuine type III₁ continuum object, outside the type I shadow in which the two readings provably coincide. The instrument returns a third verdict: the registered multi-time orientation is geometric and irreducible to any effective channel — in type III₁ the restricted state admits no density-matrix representation to dilate, so no Stinespring dilation can readmit it as "merely an ancilla," which excludes, within the stated framework, its reduction to einselection — and it simultaneously coincides with the Borchers–Wiesbrock spectral condition: the positivity of the energy rather than a new arrow, neither new physics nor an imported thermodynamic gradient. The frontier this verdict localized was then pursued with the same instrument across every in-scope regime it could reach — non-geometric flow, weak non-Gaussianity, integrable and genuine non-equilibrium, a fixed curved background, strong coupling, and a minimal quantum promotion of the geometry itself — and in every one the third verdict held: the registered orientation reduced to already-known structure (a single spectral temperature, a boost of one, an evolving Gibbons–Hawking temperature, or a functional of an effective dynamical background), with the apparatus repeatedly returning apparent positives that each dissolved under continuum and operator-level controls. A structural proposition accounts for the pattern and places any genuinely new positive outside every background-functional setting. At the one in-scope locus with no single background to reduce to — a geometry register that itself superposes and mediates between two matter parties — a first lattice measurement finds the joint multi-time record irreducible to any single shared effective classical background in its declared rival class, stably across three sizes: a record witness carrying information beyond the entanglement witness of the interferometric proposals, bounded to a figure of merit at lattice scope and grade (ii), with its field limit open. The aim of the document is documentary: every verdict is conditional on a declared chain of assumptions, every theorem and dataset lives in the companion phase records (DOIs below), and the vocabulary of decision names outcomes of preregistered, hash-frozen decision rules.