Last-Exit Valuation Boundaries: A Rust Kernel, a Hybrid Vault Wrapper and the Limits of Venue-Derived NAV

A vault can value deposited inventory by modeling its sale after outside supply rather than using the current spot price. This report examines a recovered Rust last-exit valuation kernel and its associated Solana vault wrapper at one immutable backup snapshot. The distinction between them is consequential: the kernel computes an outside-supply-first tail using uncapped theoretical curve proceeds, whereas the selected wrapper ignores outside supply and books marginal changes in uncapped current-inventory value. The wrapper also converts quote amounts through registered Pyth feeds, so its USD accounting is not oracle-free. Thirteen unchanged kernel tests and two wrapper host tests passed; one wrapper test is Anchor's generated program-ID check. No SBF, live venue or funded execution was performed. Eight parser branches contain heterogeneous validation and approximation boundaries, including an explicitly optimistic deep-exit approximation. Source inspection also identifies a feed-association assumption and three operation-specific fee ratchets. The result is a reproducible version-specific study, not proof of conservative pricing, solvency, market returns or manipulation resistance. Empowerment, financial inclusion and evidence-based accountability shape the questions and limits; no social outcome or deployed wrongdoing is established. Jarett Dunn. Technical report, version 1.0. Preprint, not peer reviewed. Codex assisted source recovery, analysis, local tests and writing. The manuscript and new analysis are CC BY 4.0; software retains its original licenses and notices.