A Smith Chart for the Riemann Hypothesis: The Cayley-Li Disk as a Unified Instrument Panel for Circle-Side Positivity (IMM Paper 19, Open Series)

This note proves nothing about the Riemann Hypothesis and presents no evidence for or against it. Its subject is instrumentation: we assemble, under one conformal coordinate system, the known ``circle-side'' positivity encodings of RH, in exact analogy with the Smith chart of radio-frequency engineering. The Smith chart is the M\"obius map =(Z-1)/(Z+1) folding the right half-plane of positive-real impedances into the unit disk, so that passivity becomes legible as geometry. Li's map z=1-1/s performs the same fold on the critical strip: RH is exactly the statement that every nontrivial zero's image lies on the unit circle, and the Li coefficients _n T: Li 1997; Bombieri--Lagarias 1999 and the Toeplitz truncations A(m) of the truncated Weil form T: Paper 14 are the boundary gauges that would register a departure. Every entry of the resulting dictionary is graded; the underlying mathematics (M\"obius geometry, Herglotz/ positive-real functions, de Branges canonical systems) is standard and credited, and the contribution claimed here is assembly and a working, tested instrument only. The instrument cross-validates against the pre-registered E-LI-1 run: a synthetic off-line quadruple at =0.1 , 98.83 drives _ (T_M)<0 first at M=272 in both implementations. https://travisbergen2.github.io/rh-smith-chart/