Artian's A6 Hard Coherence-Capacity Wall: A Source-Admissibility Postulate and Non-Stacking Theorems

A sharp upper bound on jointly coherent mass, rather than a collapse lifetime Can a jointly coherent mass keep growing without a physical ceiling? This paper states the global A6 hard-wall postulate in Artian geometry and gives it an explicit mathematical form. \[\boxed{\begin{aligned}\rho_\Gamma\in\mathcal S_{\rm coh}^{A}(\Gamma)&\ \Longrightarrow\ B_\Gamma\le1,\\B_\Gamma>1&\ \Longrightarrow\ \mathcal S_{\rm coh}^{A}(\Gamma)=\varnothing.\end{aligned}}\] Here \(B_\Gamma=M_\Gamma/m_A\) is the participating source-mass count of one coherent domain, with \(m_A=\hbar/(c\ell_A)\). An over-capacity coherent state is excluded from the physical state set, even transiently. There is no collapse lifetime or localization-rate coefficient. Distinct independently funded domains can still form ordinary macroscopic matter. The finite-dimensional realization replaces particle-count entanglement depth with a source-mass-weighted admissibility class: \[\mathfrak A_{\mathbf b}=\operatorname{conv}\!\bigcup_{\pi:\ \sum_{i\in C}b_i\le1\ \forall C\in\pi}\left\{\bigotimes_{C\in\pi}\rho_C\right\}.\] The paper proves convexity, closedness, partial-trace and local-operation stability, a coherent aggregation bound, and a prohibition on an over-budget entangling preparation. A directly checkable witness consequence is \[\boxed{\sum_i b_i>1\quad\Longrightarrow\quad\langle\mathrm{GHZ}_N|\rho|\mathrm{GHZ}_N\rangle\le\frac12\quad(\rho\in\mathfrak A_{\mathbf b}).}\] The GHZ overlap inequality is standard quantum-information mathematics. The QTT contribution is the physical mass-weighted restriction on which source states are admissible. A certified above-wall witness would falsify the proposed global postulate. The paper specifies the source-to-instrument certificate needed for that judgment, rather than counting an entire host object by convention. The relation to the existing local A6 law is explicit: common-address projection plus complete branchwise funding would imply the global wall. The complete-funding lemma is a separate derivation target; the global wall is adopted here as a postulate, not relabelled as an already-proved consequence of local capacity alone. Version 1.0 includes a self-contained onboarding route, source ontology, axiom and constructor cards, proofs, diagrams, a finite-state verifier, prior-work comparisons, and a blind-test protocol. Structural consequences are proved conditional on the postulate; experimental selection remains open. Stable paper DOI · Main Book v10.01 · A6 lexicon · Artian's Universe