Switch from Hardhat V2 to V3 to support Etherscan contract verification

[onahprosper]

User Story
As a developer, I need to upgrade from Hardhat V2 to V3, so that Etherscan contract verification works properly for our current contracts that have not yet been upgraded.

Acceptance Criteria

1. GIVEN the current Hardhat V2 setup
   WHEN upgrading to Hardhat V3
   THEN all existing scripts and configurations should continue to work

2. GIVEN Hardhat V3 is installed and configured
   WHEN attempting to verify contracts on Etherscan-based explorers
   THEN verification should succeed without compatibility issues

3. GIVEN the upgraded Hardhat setup
   WHEN running deployment and verification commands
   THEN all existing workflows should function correctly

Tech Details

• Upgrade Hardhat dependencies from V2 to V3 in `package.json`
• Update Hardhat config to use V3 syntax and features
• Update `@nomicfoundation/hardhat-verify` plugin to latest version compatible with V3
• Test contract deployment and verification on multiple networks
• Update any deprecated API calls or configuration options
• Ensure Hardhat Ignition modules work with V3
• Update CI/CD workflows if needed

Notes/Assumptions

• Current contracts are not yet upgraded to leverage V3-specific features
• V3 provides better support for modern Etherscan verification APIs
• Breaking changes between V2 and V3 should be documented and addressed
• Existing deployed contracts are not affected, only the development tooling changes