BU55 Reality Grammar under B_U Light Bending, Settlement Bandwidth, Projection-Stratum Rules, and the Reclassification of Observable Physics

This paper develops BU55 as a reality-grammar interpretation of observable physics under Single-Universe Boundary Consistency, B_U. Its central claim is that light-speed, time, space, causality, energy, momentum, particles, and fields are not ontic building blocks, but projection-layer rules formed after total reality passes through microscopic zeroing, finite projection, coherent retention, and settlement sealing. BU50 defines the appearance-side minimal admissible structure as the first lawful nonzero standing after a cleared background; BU55 extends that logic to the grammar by which the observable world remains readable, auditable, reusable, and settleable. The paper reclassifies light bending under gravity as the geometric manifestation of a zero-debt path. Mass does not alter the global fixedness of B_0; it changes the local geometric readout, path-cost structure, and propagation-settlement conditions inside the projection window. Light, as a lawful retained optical state, propagates along paths that satisfy microscopic zeroing, fast-slow orthogonality, coherent propagation, payable information-update cost, and settlement stability. The backward mirror reads this as geodesic motion and gravitational light bending. BU55 further defines light-speed as settlement bandwidth, time as settlement sequence, space as settlement position, causality as coherent relation posted into the ledger, and energy-momentum as finite projection balance. Observable reality is treated as a settlement summary of total reality within a finite-bandwidth interface, not as the ontic totality itself. An intuitive financial-trading-system analogy is added: B_U is the immutable core ledger, spacetime and causality are settlement disciplines, light-speed is window bandwidth, particles and fields are settlement balances, entanglement is multi-window ledger consistency, and light bending is the market curve of a zero-debt path.