feat(wallet-cli): add daemon JSON-RPC socket transport

[sirtimid]

Explanation

@metamask/wallet-cli runs a background daemon that hosts a @metamask/wallet instance; the CLI talks to it over a Unix socket. This PR adds that transport layer. It is purely additive plumbing — no mm subcommand consumes it yet (commands land in a follow-up), so there is no user-visible behavior change.

• socket-line — writeLine/readLine for newline-delimited framing over a net.Socket, with an optional read timeout and listener cleanup.
• daemon-client — sendCommand opens a connection, writes one JSON-RPC request, reads one response, and closes; it correlates the response id with the request and retries once on transient connection errors (ECONNREFUSED/ECONNRESET). pingDaemon is a lightweight getStatus health probe that distinguishes "no daemon" (absent) from "daemon present but unreachable", classifying the latter by failure mode (refused / timeout / permission / protocol / other).
• rpc-socket-server — startRpcSocketServer listens on a Unix socket and dispatches one JSON-RPC request per connection to a handler map. It intercepts a built-in shutdown method, enforces one-request-per-connection, times out idle connections, and returns a close() handle.
• daemon-spawn — ensureDaemon spawns a detached daemon process and polls until the socket is responsive, refusing to take over a wedged or foreign-owned socket. Resolves the entry point from dist (prod) or src via tsx (dev).
• stop-daemon — stopDaemon escalates from a graceful shutdown RPC through SIGTERM to SIGKILL, then removes the PID and socket files best-effort.
• prompts — confirmPurge wraps the ESM-only @inquirer/confirm via dynamic import.
• types — adds RpcHandler, RpcHandlerMap, DaemonStatusInfo, and DaemonSpawnConfig.

Adds @inquirer/confirm and @metamask/rpc-errors dependencies. Every daemon module is covered to the package's 100% coverage thresholds, plus a socket-integration.test.ts that exercises the client and server together over a real Unix socket (framing, id correlation, the one-request-per-connection invariant, and real shutdown timing).

References

• Builds on feat(wallet-cli): add SQLite-backed controller-state persistence #9067 (the wallet-cli persistence layer). This PR is stacked on that branch and should merge after it; GitHub will retarget it to main once feat(wallet-cli): add SQLite-backed controller-state persistence #9067 merges.

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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[socket-security]

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	@​inquirer/​confirm@​6.1.1

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