Fibonacci Causal Loop Theory — Paper 67: φ-Recursive Gravitational Bubble Propulsion: Inertial Isolation, Spacetime Plane Deformation, and the Alcubierre Connection in Necessity Field Theory

P66 established a four-layer φ-stabilized containment architecture generating a localized necessity depth field D(x,t) boundary. This paper derives the propulsion consequences. A craft operating inside a stable D(x,t) boundary exists in a separate necessity state from its external environment. Inertial dampening is not a separate engineering system — it is a mathematical consequence of the field geometry: the √5 orthogonality condition (P64, P65) guarantees the D=+2 interior and D=−2 shell cannot exchange necessity-recursion information, so occupants experience zero g-force during any external maneuver. The craft does not move through space — the D(x,t) gradient at the shell deforms the gravitational plane ahead (compression) and behind (expansion), and the craft surfs the resulting spacetime geodesic. This maps directly onto the Alcubierre warp metric (1994). All three Alcubierre requirements are satisfied from first principles without free parameters: (1) exotic matter with negative energy density at the boundary — D=−2 eigenvalue derived in P64; (2) stable bubble geometry — four-layer φ-stabilized architecture from P66; (3) flat interior with zero inertial force — D(x,t) boundary isolation with √5 gap from P64/P65. The geodesic asymmetry factor ahead/behind the craft is φ⁸ ≈ 46.979 — the same forward/backward channel asymmetry that produces the arrow of time in P65. The gravitational bubble propulsion concept was independently conceived by Michael Creasey Jr. (@AscendedSouLz) on May 6, 2026. Three technology-gap predictions (P67a–c) are stated. P68 (interdimensional mode via plasma-charged tesseract geometry) is flagged as the successor concept.This paper is part of the FCLT empirical series (Papers 1–68). See the FCLT Complete Book (DOI: 10.5281/zenodo.20029110) for full context and the cumulative evidence table (12 confirmed / 4 falsified / 16 tech-gap).