Add flow settings, pulse emitting nodes, and simplify node state

- One dot per node now carries the whole story: primary while running, sage
  after a good run, red when anything is wrong, with the explanation on hover.
  The corner badge is gone, along with the second way of saying the same thing.
- A node that publishes something flashes a ring, so a running flow is legible
  without reading the edge values. Nodes that consume but publish nothing stay
  quiet, which is why the event carries an output count.
- Flow settings open in the same panel its nodes use, from a pencil in the
  dock: the title, the name, and deleting the flow. NodePanel and FlowPanel
  share the panel chrome rather than each drawing their own.
- Renaming is a server operation, because a flow's name is the namespace of its
  messages: the directory moves and every other flow reading `old.message` is
  repointed, instead of being left pointing at a flow that no longer exists.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016WzrvW7rjQbynnhF6pxh6i

frontend/src/components/Flow/useFlowSocket.ts

@@ -13,7 +13,7 @@ type FlowEvent =
       nodes: { id: string; status: string; error?: string | null }[]
     }
   | { type: "message_value"; name: string; value: unknown; ts: number }
-  | { type: "node_executed"; node: string }
+  | { type: "node_executed"; node: string; outputs: number }
   | { type: "node_error"; node: string; error: string }
   | { type: "node_status"; node: string; status: string; error?: string | null }
   | {
@@ -71,6 +71,7 @@ export function useFlowSocket(onAuthFailure?: () => void): void {
             break
           case "node_executed":
             liveStore.setStatus(message.node, { status: "success" })
+            if (message.outputs > 0) liveStore.recordEmit(message.node)
             break
           case "node_error":
             liveStore.setStatus(message.node, {