feat: implement multisig sync sign flow over WalletConnect [PERA-3782] [PERA-3780]

[yasincaliskan]

Description

• Implements the multisig sync flow: a dApp can request a signature from a multisig account over WalletConnect and receive the fully assembled signed transaction back on the same connection

Multisig sign handoff

• When a dApp sends a multisig sign request over WC, the request is registered with the backend and tracked via a process-wide handoff registry (walletConnectHandoffs).
• An app-root resolver hook (useWalletConnectHandoffResolver) polls the backend until participants reach the signing threshold, then assembles the signed msig bytes (assembleSignedMultisigTransactions) and delivers them to the dApp.
• Poll outcomes are classified by a pure, unit-tested classifyHandoffPoll (ready / soft-reject / error / keep-polling), with exponential backoff.
• Sign requests are marked confirmed via useMarkSignRequestsConfirmedMutation.

Bridge-socket recovery

• WC v1 sessions own a single bridge WebSocket the OS suspends on background; v1 silently queues outgoing messages into the dead socket, so a signed response never reaches the dApp despite a "success" UI.
• New connectorRegistry owns the connector map plus socket-liveness checks: ensureConnectorReady recreates a connector from its stored session when the socket is dead (escaping the zombie-socket reconnect deadlock).
• useWalletConnectForegroundReconnect warms all dead sockets on every background -> foreground transition.

Related Issues

• https://algorandfoundation.atlassian.net/browse/PERA-3782
• https://algorandfoundation.atlassian.net/browse/PERA-3780

Checklist

• Have you tested your changes locally?
• Have you reviewed the code for any potential issues?
• Have you documented any necessary changes in the project's documentation?
• Have you added any necessary tests for your changes?
• Have you updated any relevant dependencies?