Move HCA to ens-modules repo

[zeroknots]

Move HCA to ens-modules repo

Moves the HCA (Hardware-Controlled Accounts) implementation and module contracts out of ens-contracts-v2 and into the ens-modules repo. The factory and context contracts remain here.

What stays in this repo

• HCAFactory — Deploys deterministic NexusProxy instances via CREATE3, keyed by primary owner. Supports idempotent createAccount and owner-controlled implementation upgrades via setImplementation.
• HCAContext / HCAContextUpgradeable — Base contracts that wire up factory references and UUPS upgrade guards for HCA account implementations.
• HCAEquivalence — On-chain equivalence checking for HCA deployments.
• ProxyLib — Library for proxy deployment operations.
• Interfaces — IHCAFactory, IHCAFactoryBasic, IHCAInitDataParser.
• Tests — Unit tests for HCAContext, HCAContextUpgradeable, and HCAEquivalence.

What moved to ens-modules

• HCA — The account implementation (extends Nexus with locked-down module config, NFT rejection, upgrade guards).
• HCAModule — The validator module (extends OwnableValidator with HCA-specific constraints).
• OwnableValidator — Base ERC-7579 validator with multi-sig, owner expiration, and dual validation modes.

Other changes

• Added a README to the HCA directory linking to the full HCA documentation.
• Gas improvements and cleanup.

Improvements

the deployment gas cost was reduced by approx 140.000 gas units

@TateB unfortunately the diff is quite large due to linting. could you run linting on feat/hca-clean so the diff gets smaller?