Advisory issues read as advice rather than failure

`ADVISORY_ISSUES` moves next to `ValidationIssue` in pipeline.py, and the
model derives an `advisory` flag from its own code, so the distinction the
engine already made ships to the client instead of being re-guessed there.

The dock keeps its summary in `--destructive` only when a real fault is
among the issues and paints an advisory row `--muted-foreground`; the
canvas leaves advisories off a node's dot and border entirely, since node
status has three colours and no warning tier.

biome checks the generated `openapi.json`, which nothing formats since the
SDK script dropped its format pass — ignore it like the other generated
files.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013Gf7WaExcJ9bs3kfJXB3nK

backend/fluksio/flow/controller.py

@@ -54,6 +54,7 @@ from fluksio.flow.nodes import (
     TriggerNode,
 )
 from fluksio.flow.pipeline import (
+    ADVISORY_ISSUES,
     NodeOutcome,
     Pipeline,
     RunCacheLookup,
@@ -81,10 +82,6 @@ logger = logging.getLogger(__name__)
 
 HOOK_PREFIX = "/hooks"
 
-# Validation codes that are worth saying but do not stop a flow running, so
-# neither the brain graph nor the health summary treats them as a fault.
-ADVISORY_ISSUES = frozenset({"unauthenticated_hook"})
-
 # How long a node gets to close what it opened before the rebuild moves on.
 # A node's `stop` talks to whatever it connected to, and a broker that has gone
 # away can leave it waiting for an acknowledgement that never arrives — which