jobq-wire: move the generic graph projection into its own crate

The wire types were in hive-host-sock, which is the host *socket* crate — so
anything living there is core-shaped by construction, and the projection had
quietly grown two core dependencies to match: it selected roots by matching
NodeKind::Dag, and rendered payloads through free functions in hive-c0re that
nothing obliged a second host to write.

hive-jobq is the wrong home too. That crate is the scheduler — logic — and
folding presentation in means every consumer of it carries a JSON vocabulary
it may never serve.

So: a new hive-jobq-wire. A host implements WireNode for its payload N and
WireResource for its resource name R; GraphWire::wire_snapshot is
blanket-implemented for Graph<N, R> when both hold, and for nothing else. A
payload that has never said how it displays has no way onto the wire.

wire_snapshot takes the roots to serve rather than reading Graph::roots
itself. Nothing is ever removed from a Graph, so retention is a policy only
the host can hold; hive-c0re passes visible_roots(), which is the existing
MAX_HISTORY_DAGS bound selected structurally (a root is a node with no
parent) instead of by node kind.

CLAUDE.md

@@ -63,6 +63,13 @@ hand-maintained per-file tree drifts out of sync with the code.
   remaining `job_queue/` module is the c0re-specific layer *over* this
   crate, and is being removed in favour of it — new scheduler-shaped code
   belongs here, not there.
+- **`hive-jobq-wire/`** — wire types for serving a `hive-jobq` graph to a
+  viewer, plus the `WireNode` / `WireResource` traits a host implements to
+  say how its `N` and `R` render. Deliberately *not* part of `hive-jobq`:
+  that crate is logic, this is presentation, and folded together they
+  remix. `GraphWire::wire_snapshot` is blanket-implemented for any
+  `Graph<N, R>` whose parameters implement both — so a payload that has
+  never said how it displays cannot reach a viewer at all.
 - **`hive-screen-mcp/`** — stdio MCP bridge for GUI agents
   (`hyperhive.gui.enable`): `screenshot` via `grim`, `type_text` /
   `key_press` via `wtype` (Wayland virtual-keyboard protocol), and