The view: one read-only bus user for a page in a browser, composed like every other (hq research 036)

Research 036 names the gap (G1): no way for a browser to reach the bus. The bus module now listens
over WebSocket (mesh-catalog, nats); this is who connects there. The view is a fixed principal
(broker.KindView, user `view`) composed into the user list like every user once its credential is
minted, and left out once it is forgotten: it subscribes the issue tracker's events (opened, moved,
noted, linked), the controller's plan-moved and condition-raised/changed/cleared, and the delivery
owner's transition and group; it publishes only the JetStream API requests a read-only watcher of
the tracker's bucket (mesh-issues_issues) makes — STREAM.INFO, DIRECT.GET, CONSUMER.CREATE/INFO/
DELETE, flow control — answered in its own inbox; no reply, no tool, no event, no `$KV` write.

`bus view-credential` mints and prints it once (hash kept, like a person's); `bus view-revoke`
forgets it, real at the next composition. Tests: the composed grants are exactly these and a write
grant of any shape fails; the view is composed only once minted; and against a real server read from
the composed file over WebSocket, the view binds the bucket, reads a key, watches a put land, and is
refused a put, a delete and an event, the bucket unchanged.

internal/inventory/bususers.go

@@ -45,6 +45,9 @@ const (
 	// BusNodeTools is a machine's tool runtime (novox/hq ADR 0175): named like the module it
 	// stands for, recorded as what it is.
 	BusNodeTools = "node-tools"
+	// BusView is the one read-only view onto the bus (broker.KindView): its row is the whole record of
+	// it, minted by `bus view-credential` and forgotten by `bus view-revoke`.
+	BusView = "view"
 )
 
 // MintBusPassword makes a bus password and records its hash under a username, replacing whatever was