WIP OToken Vault Oracles

[naddison36]

Summary

Adds immutable Vault-backed price oracles for OETH, OUSD, and superOETHb.

Each oracle reports the value of one OToken in its Vault’s underlying asset:

price = vault.totalValue() * 1e18 / oToken.totalSupply();

Prices use 18 decimals and are exposed through:

• price()
• latestAnswer()
• Chainlink-compatible latestRoundData()
• Chainlink-compatible getRoundData(1)

The OToken address is resolved directly from the configured Vault to prevent mismatched Vault/token deployments.

Deployments

Ethereum Mainnet

Deployment	Vault constructor argument	Description
OETH_VAULT_ORACLE	OETH_VAULT_PROXY (0x39254033945AA2E4809Cc2977E7087BEE48bd7Ab)	OETH / WETH
OUSD_VAULT_ORACLE	OUSD_VAULT_PROXY (0xE75D77B1865Ae93c7eaa3040B038D7aA7BC02F70)	OUSD / USDC

Base

Deployment	Vault constructor argument	Description
OETHBASE_VAULT_ORACLE	OETHBASE_VAULT_PROXY (0x98a0CbeF61bD2D21435f433bE4CD42B56B38CC93)	superOETHb / WETH

The Foundry deployment scripts verify the Vault, OToken, description, decimals, version, and that the returned price is positive. No governance actions are required.

Behavior

• Returns 1e18 when Vault value and OToken supply are equal.
• Increases above 1e18 as unreleased yield accumulates between rebases.
• Can return below 1e18 if the Vault becomes insolvent and its assets are worth less than the outstanding OToken supply.
• Does not apply a price cap, floor, or peg adjustment.
• Reports the raw ratio between the Vault’s assets and the OToken supply.
• Supports OUSD’s 6-decimal USDC underlying because Vault.totalValue() is normalized to 18 decimals.
• Reverts with No data present when OToken supply is zero.
• Uses a synthetic Chainlink round ID of 1; the price is calculated live rather than historically stored.

Testing

Added concrete and fuzz coverage for:

• Constructor configuration
• Price at rebase
• Accumulated yield and prices above one
• Fractional prices
• Zero supply
• Chainlink-compatible accessors and metadata
• Arbitrary total-value/total-supply ratios

Operational impact

The deployed oracle names and callable interface are not currently referenced by Talos actions. No curated action ABI, pinned address, or existing Hardhat deployment artifact requires updating in this PR.

Code Change Checklist

• Contract code is complete
• Executable Foundry deployment files
• Fork verification after deployment
• Unit and fuzz tests
• Owner full checklist review
• Two internal approvals