Paper 0.5: A Study of the Displacement-Record Mechanism — Recording of Displacement by Interference of ν Oscillation and the Complex Plane, and the Composition of Two ±1/2 (±1)

A definition paper in the series "The dual geometry of wavelength space and frequency space." With zero added axioms, it makes precise the internal term displacement record (avoiding the word "observation," which would imply apparatus interaction). From the basic assumptions (2.5: νλ=1, zero-point δ=±1/2, asymmetric one bit) and their implicit definitions, a change Δθ is recorded as a difference of interference intensity values against the ν oscillation as reference. Key results, carried to the paper's own rigor standard: (i) the reading of φ is fixed to the winding-number (progressive) reading, leaving a reflection degeneracy under an equal-frequency premise, consistent with the series' sign sector (Paper 13); (ii) the composition of two ±1/2 ambiguities (source value + sampling) is treated by interval arithmetic: ≤±1 is axiom-free (subadditivity), while =±1 holds under endpoint reachability (not independence; only anti-correlation breaks it); distribution shape (triangular, σ=1/√6) requires extra probabilistic assumptions and is not used; (iii) source-value vs sampling ambiguity is indistinguishable as a 2-DOF→1-DOF information projection. The arrow of time is not derived (Page–Wootters analogy); Hartle's "start with records" slogan is shared but decoherent histories are not implemented. Bilingual (English and Japanese) documents, with a verification script and an exact-computation figure. No physical identification is made.