Adds a long-running daemon process to the OCAP kernel, managed via new
`ocap daemon` CLI subcommands. The daemon spawns as a detached child
process, exposes the kernel's RPC service over a Unix domain socket
(`~/.ocap/daemon.sock`), and auto-starts on first `exec` invocation. The
kernel database is persisted at `~/.ocap/kernel.sqlite`.

Supersedes #842, and defers the introduction of its notion of a "console
vat" and repl / IO functionality to a later date.

### New CLI commands

- `ocap daemon start` — start the daemon (or confirm it is already
running)
- `ocap daemon stop` — gracefully shut down the daemon
- `ocap daemon purge --force` — stop the daemon and delete all persisted
state
- `ocap daemon exec [method] [params-json]` — send a JSON-RPC call to
the daemon (defaults to `getStatus`)

### Kernel changes

- `makeKernel()` now returns `{ kernel, kernelDatabase }` and accepts
optional `systemSubclusters`
- `ifDefined` utility moved from `kernel-agents` to `kernel-utils`
- `startRelay` moved from `cli` to `kernel-utils/libp2p`

### New modules

- `@ocap/nodejs/daemon` — daemon orchestration (`startDaemon`,
`deleteDaemonState`, `startRpcSocketServer`, socket line protocol)
- `@ocap/cli/commands/daemon*` — CLI-side daemon client, spawner, and
command handlers




<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **High Risk**
> Adds a new local RPC control plane (daemon + socket server) and
changes kernel construction/IO-channel semantics, which can impact
process lifecycle, persistence, and local security posture (e.g.,
arbitrary SQL via `executeDBQuery`).
> 
> **Overview**
> Adds a detached, long-running OCAP daemon that hosts kernel JSON-RPC
over a Unix domain socket and persists state under `~/.ocap`, with new
`ocap daemon start|stop|purge|exec` commands (including auto-spawn on
`exec`) and prototype safeguards/behavior documented.
> 
> Introduces `@ocap/nodejs/daemon` (RPC socket server, line protocol
helpers, daemon start/stop + state deletion) and updates `makeKernel` to
return `{ kernel, kernelDatabase }` (plus optional `systemSubclusters`)
to support the daemon lifecycle.
> 
> Refactors shared utilities by moving `startRelay` to
`@metamask/kernel-utils/libp2p` (and shifting libp2p deps accordingly)
and moving `ifDefined` into `@metamask/kernel-utils`; updates
tests/scripts and fixes `makeSocketIOChannel` reads to block until a
client connects (instead of returning `null`).
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
c0adc26. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

---------

Co-authored-by: grypez <143971198+grypez@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>