Draw a node that is down as a troubled neuron

`brain_graph` read `self.issues` alone, which is what a build found — so a
node that loaded and then lost its device was a well neuron on Home, and
that is what someone comes to this view to find.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KYM38KSb4V4v2T71eifnZv

backend/fluksio/flow/controller.py

@@ -1497,10 +1497,12 @@ class FlowController:
         compiled pipeline, so a node that failed to load still appears — a
         broken neuron is exactly what someone comes to this view to find.
         """
-        # What validation found, by the node it names. A cycle names every node
-        # in it, so all of them are marked rather than an arbitrary one.
+        # What validation found, by the node it names, plus what is down right
+        # now — a neuron someone comes here to find is as often a node that
+        # stopped working as one that never built. A cycle names every node in
+        # it, so all of them are marked rather than an arbitrary one.
         troubled: dict[str, str] = {}
-        for issue in self.issues:
+        for issue in self.issues + self._health_issues():
             if issue.code in ADVISORY_ISSUES:
                 continue
             for member in (*issue.nodes, *filter(None, [issue.node])):