feat(ngz): add No-Going-Zone onchain habit accountability action provider

[bennytimz]

Summary

Adds a new action provider for No-Going-Zone (NGZ), an onchain habit accountability tracker deployed on Base.

NGZ lets users declare habits, check in daily to build streaks, earn soulbound milestone NFTs at 7/30/90/180/365 days, and face permanent onchain consequences (Wall of Shame NFTs) when they relapse. All data lives onchain — no backend, no database.

Actions Added

Read-only (no wallet required)

• get_ngz_leaderboard — Fetch top streak holders ranked by current streak
• get_ngz_user — Look up a user's full stats by wallet address
• get_ngz_wall_of_shame — Fetch recent relapse events from the Wall of Shame

Write (wallet required)

• check_in_ngz — Record today's check-in to maintain your onchain streak
• tip_ngz_user — Send ETH respect directly to another user's wallet (100% goes to recipient, no fee)

Implementation Notes

• Read actions use viem's createPublicClient to query the NGZ contract directly — no external API dependency
• Write actions use the WalletProvider interface so they work with any wallet (CDP, Privy, viem, etc.)
• Supports base-mainnet and base-sepolia
• Contract address: 0x4D1b5da45a5D278900aedfc6c96F0EE0D4e28bF6 (Base Sepolia — mainnet deployment in progress)
• All actions return structured JSON strings following the existing provider pattern

Tests

16/16 tests passing. Coverage includes:

• Happy path for all 5 actions
• Empty/zero state responses
• Contract and transaction failure handling
• Network support validation

Checklist

• Tests added and passing (pnpm test -- --testPathPattern=ngz)
• Lint passing (pnpm run lint)
• Format passing (pnpm run format)
• Changeset created
• Export added to action-providers/index.ts
• README included

[cb-heimdall]

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