feat: add ExecutionBoundEnforcer — exact execution commitment at redemption

[terriclaw]

What?

• Add ExecutionBoundEnforcer, a CaveatEnforcer that binds execution to an EIP-712 signed commitment at redemption

Why?

• Existing caveats enforce policy constraints, not exact execution
• Offchain calldata construction can drift within allowed bounds
• Requires exact equality between execution and a signed commitment

How?

• Inherits CaveatEnforcer
• terms: unused
• args: abi.encode(ExecutionIntent intent, address signer, bytes signature)
• ExecutionIntent: (account, target, value, dataHash, nonce, deadline)
• dataHash = keccak256(execution.callData)
• Nonce scoped by (delegationManager, account, nonce)
• Nonce is consumed before signature verification (CEI)
• Supports EOA + ERC-1271 signatures via SignatureChecker
• Restricted to single-call + default execution mode

Closes #172

[terriclaw]

addressed both issues:

1. authorizedSigner moved to _terms — delegator now commits to the trusted signer at delegation time. _args carries only (intent, signature).
2. nonce scoped by msg.sender (delegation manager) — direct beforeHook calls use a different scope and cannot grief legitimate redemptions. added test_directCall_cannotGriefNonce to prove this.

10/10 tests passing.

[terriclaw]

good catch — switching to OZ EIP712 base removes the custom cached domain separator and matches DelegationManager's behavior on chainId changes. _hashTypedDataV4 now handles digest construction dynamically.

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Reviewed by Cursor Bugbot for commit 118ead0. Configure here.}

[terriclaw]

good catch — moved nonce consumption before signature verification to follow CEI. also removed the incorrect NatDoc justification; the ordering is for CEI compliance, not griefing prevention (revert rolls back state regardless).

[terriclaw]

tightening pass: fixed stale NatDoc comment — nonce is consumed before signature verification (CEI), not after. the previous wording was left over from an earlier iteration and incorrectly described the ordering.
no logic changes. 10/10 tests passing.