predict: gate mints and pool flushes on a certified pricing-error bound

[0xaslan]

Summary

• Predict carries a signed center-radius Approx from option pricing through payout-tree valuation and pool NAV.
• Pricing now has one canonical, decomposed 1e9 evaluator; the parallel u128/1e18 certificate evaluator has been removed.
• Mint and pool-NAV policy gates use the certified radius with true-value-relative limits of 0.1% and 1%.

Why

• Predict prices digital options from an SVI implied-variance surface in fixed point. Mint admission consumes contract prices, while the periodic full-pool valuation consumes the resulting NAV.
• The previous implementation evaluated the formula twice: once at 1e9 for the protocol value and again at 1e18 for its certificate. That duplication obscured which part of the formula actually needs retained precision.
• This draft establishes the mechanical all-1e9 baseline needed to measure liveness before widening one minimal contiguous pricing component.

Linear / Context

• Ticket: to be linked.
• Builds on the read-only NAV correction merged in predict: value knocked-out orders at liquidated worth in the NAV correction (DBU-605) #1153.
• The short-dated precision defect remains tracked as P-14 in packages/predict/predeploy/open-items.md.

Key Decisions

• This is an intentionally known-red experimental checkpoint, not a merge-ready state. Tests that need to mint on the default surface remain live and fail at the precision gate; they are not re-pinned or marked as expected failures.
• Existing architectural simplifications remain: Approx is carried through the price memo, signed payout-tree walk, liquidation correction, expiry NAV, and pool NAV; tick-to-strike conversion remains owned by range_codec.
• Independent soundness fixes remain in the baseline: sigma-squared births its fixed-point rounding error, a rounded zero slope does not discard a possible smile correction, and relative-error checks use the lowest possible true value as their denominator.

Scope / Descoped

• No retained 1e18 pricing island is included in this checkpoint.
• No test fixtures or economic outputs are changed to make the suite green.
• Real-surface liveness analysis is deferred until a minimal precision island reduces the unit-test failure count below the experiment threshold.

Test Plan

• sui move build --path packages/fixed_math --warnings-are-errors
• sui move build --path packages/predict --warnings-are-errors
• sui move test --path packages/fixed_math --gas-limit 100000000000 — 151 passed
• sui move test --path packages/predict --gas-limit 100000000000 — 449 total, 369 passed, 80 known-red
• Classified all 80 Predict failures: 79 abort at strike_exposure::EPriceTooImprecise; one directly asserts that the same default price should certify
• python3 packages/predict/predeploy/check.py
• Pinned Move formatting

Risk / Rollout

• Draft only; do not merge this checkpoint. The compositional 1e9 radius makes the normal production mint unavailable.
• The next increment should retain higher precision only across the smallest variance-to-d2 island that materially restores liveness, then validate the surviving failure set before real-surface analysis.