Wallets and user onboarding (v1)

[holic]

We've been prototyping a complete wallet integration and user onboarding flow in #2623

This issue will capture what we have left for a v1 and replaces some previous issues.

This new library/package will be wired up in the same way you might wire up RainbowKit or ConnectKit, where it sits within a Wagmi provider and leans on the Wagmi config for defaults. It will expose an appAccountClient that is populated once a user has fully onboarded (wallet connected, app account funded and registered into the world).

• Get Unstable_CallWithSignatureModule audited
• Rip out smart account and gas tank stuff for now
• Finalize designs
  • Implement designs
• Clarify "gas tank balance" analogy
• Properly calculate gas required for "withdraw all funds"
• Solidify assumptions: for MUD apps on OP Stack chains
• Onboarded = all requirements fulfilled and balance > 0
• Consistent error+pending states and async operations (e.g. deposits)
• Revisit button pending states
• UI page in sandbox to show various states for easier design iteration
• Add tests for critical paths
• Explore remote iframes for isolation and automatic upgrades
  • wallet connection lives in parent window, app account lives in iframe
  • account kit package mounts the remote iframe, sets up message bus(es)
  • some message bus for account kit iframe to trigger wallet actions (e.g. signing messages and txs, switching network, etc.)
  • some message bus for app account client in parent window to trigger actions on app account
    • or, more simply, just pass the app signer PK up to the parent window?
• Explore what is required to move away from RainbowKit to our own UI (not a v1 blocker)
• Explore mobile support (not a v1 blocker)
• Add to templates

[holic]

Some additional reminders for myself:

• rename config.appInfo to config.app for alignment with upcoming app metadata
• remove config.gasPerAction and config.calldataPerAction in favor of gas tank gauge analogy
• add "url" suffix to config options that are URLs?
• add "learn more" config option to align with RainbowKit? also check for ConnectKit app metadata alignment
• move rainbowkit usage into core (and into iframe portal) in prep for replacing it with something else
• use wagmi config subset rather than the full thing excluding client?
• use "wallet" abstraction instead of "connector" in config so we can get extra metadata like wallet name, icon, etc? (see RainbowKit for example)
• add wagmi/viem/react peer deps for using account kit import as a wrapper around global
• chains should use our own type to include icon URL, bundler URL, etc.
• figure out how to include foundry chain by default without causing errors related to talking to a node that may not be listening/running (can't do this conditionally at build time since it'll be a remote script)
• expose some notion of external store on global/instance (need to factor in app account client vs prepared app account client)
• figure out how to expose things like usePreparedAppAccountClient exported from core
• upgrade to zustand v5?
• internal stores in core (e.g. useAccountModal) should be constructed as part of initializing account kit, not during import time
• see if we can tap directly into these internal core stores rather than SyncStore to avoid undefined sprinkled everywhere
• revisit resolveJsonModule and strong types when importing ABI from .json.d.ts files