feat(integrations): Delegatable Integration & Subscription Enforcer (#56)

[s6pa1rta3n-lab]

Summary of Changes

Closes #56

This PR adds the Delegatable smart contract framework integration and the DistrictERC20PermitSubscriptionsEnforcer for gas-less recurring subscriptions to TurboETH.

Key Features & Deliverables:

• Smart Contract Artifacts: Added essential Delegatable V0 smart contract artifacts (delegatable-abi, district-erc20-permit-subscriptions-enforcer-abi, and verifying-contract-erc20-permit-subscriptions-abi along with corresponding bytecode artifacts).
• Wagmi Configuration: Configured wagmi.config.ts and generated TypeScript hooks for Delegatable and enforcer contracts.
• Components:
  • FormDelegatableSubscriptionStart / FormSubscriptionStart: Interface to sign ERC-2612 permits & EIP-712 delegations off-chain and activate recurring subscriptions.
  • FormDelegatableSubscriptionRevoke / FormSubscriptionEnd: Interface to revoke or cancel subscriptions on-chain or locally.
  • DelegatableSubscriptionList: Queue and status view for managing scheduled subscriptions.
  • DelegatableSubscriptionCronStatus: Status dashboard for the automated relayer cron job.
• Client Database & Hooks: Dexie IndexedDB integration (useLiveQuery) for client-side storage of active delegations, permits, and subscription state.
• Automation / Relayer Cron: Configured Vercel cron route (/api/delegatable/cron running */30 * * * *) in vercel.json to batch execute due payments via verifyingContract.invoke().
• Application Pages: Registered integration in data/turbo-integrations.ts, accessible at /integration/delegatable-subscription and /delegatable/subscription.

Payout Routing

• EVM (Base/Arbitrum/Polygon/ETH): 0xF46C9F6d70C50BF81ef3588AB523a90a594a2F89
• Stellar: GCL6OXAMLD75BMTINA6EMRUDWK5THQUSHMYNLSNBCJAPZJHNYJTUNIBC