Capability report: PUT /devices/{id}/report, a Capabilities section, offline devices degraded

A device reports its board, screen, camera and ports from its own
credential (16 KB, schema 1, replacing the last report), and the flows
are validated against it again. The node panel turns a reported port's
config schema into a form, a reported screen is a canvas preset and a
touch screen's first report turns Touch friendly on. An offline device
node is degraded: amber on the canvas, a warning on Home, never a fault.

docs/interface/flow-editor.md

@@ -40,8 +40,9 @@ streaming toggle.
 A **Device** node stands for a paired device instead: pick the device, then
 its ports under **Publishes** and **Follows** (see
 [the device's own ports](dashboards.md#the-devices-own-ports)). A device that
-reports its ports offers them in a list with their type filled in, and the
-command palette offers each one as a shortcut, such as *Hallway camera*.
+reports its ports offers them in a list with their type filled in and a form
+for the settings each one reads, and the command palette offers each one as a
+shortcut, such as *Hallway camera*.
 
 Message fields suggest existing names. Matching an output's message is how
 you connect an input.
@@ -156,7 +157,8 @@ conflict. Reload and review their changes before retrying.
 The canvas reports unconnected inputs, missing starting values, cycles and
 code-load errors. These prevent the affected flow from running. Unauthenticated
 webhooks are advisory; runtime node-health problems clear when the node
-recovers. See [Flow issues](../concepts/flows.md#when-a-flow-needs-attention).
+recovers. A degraded node, such as a device node whose device is offline, is
+marked amber: it is a warning, and the flow keeps running. See [Flow issues](../concepts/flows.md#when-a-flow-needs-attention).
 
 ## See also