Directional Anisotropy Gravity DAG — Substrate Sector, v11: Quantum Kinematics and Direction-Orbit Coupling Hamiltonian

v11 of the DAG substrate sector. Replaces v10. This version restricts scopeto the mathematically controlled core: the single-excitation Hilbert spaceC^6 per node, the Shannon/von Neumann coincidence theorem, the tensor-networkarea law, the Direction-Orbit Coupling (DOC) Hamiltonian, the open-systemderivation of the memory field via Nakajima–Zwanzig / Born–Markov, thesemiclassical limit via adiabatic elimination (restoring forceΓ_rel = 12 η²/Γ_dec), discrete U(1) gauge links on the substrate graph,decoherence / pointer basis, and the effective DOC sound speed. All speculative programme material (extended 18-channel substrate,axis-pair doublet hypothesis, SM gauge structure, three generations,anomaly cancellation, Higgs sector, running couplings, TOE Lagrangian,cosmogony, constants) has been moved to a companion paper,"DAG Substrate sector — Gauge Structure Programme, v1".10.5281/zenodo.19614270 Changes from v10:- corrected Lindblad sum index (I=1..6 rather than I≠J)- completed single-node equation of motion- new §9.3 "Effective sound speed from DOC"- 10 new bibliography entries- scope narrowed to substrate-core content only