feat: add score-gated DOS domain policy

[JOY (JOY)]

Summary

• Add EIP-712 score-gated claim, renewal, and reclaim policy for .dos names.
• Add an access-controlled registrar and a Testnet 3939 deployment script that hands off registrar and renew roles from the legacy public registrar.
• Dynamically discover registrars in the BENS-compatible subgraph.

Validation

• forge test --match-path test/unit/registrar/DosDomainPolicy.t.sol (23 passing)
• forge test --match-path test/unit/registrar/ETHRegistrar.t.sol (36 passing)
• Subgraph Matchstick tests, manifest tests, codegen, and build (31 + 9 passing)

[gemini-code-assist]

Code Review

This pull request introduces a score-gated domain policy and a policy-controlled registrar (DOSPolicyRegistrar and DosDomainPolicy) for .dos domain registrations on the DOS Testnet, integrating EIP-712 voucher validation. It also updates the subgraph to dynamically discover and index these new registrar sources. The review feedback suggests a gas optimization in DosDomainPolicy.sol's label validation loop by skipping the first and last characters, which are already verified as alphanumeric.

[gemini-code-assist]

The loop in _validateLabel currently iterates over the entire label length, checking every character. However, the first character (value[0]) and the last character (value[length - 1]) are already validated to be alphanumeric on line 466. We can optimize this loop to start at index 1 and end at length - 1 to avoid redundant checks and save gas on every label validation.

        for (uint256 i = 1; i < length - 1; ++i) {
            bytes1 character = value[i];
            if (character != "-" && !_isAlphaNumeric(character)) {
                revert InvalidLabel(label);
            }
        }