fix(web): entity Relations panel was missing true incoming edges

fetchGraph({root, depth:1}) is backed by blast_radius, which only
walks outgoing edges — so it could never surface an edge some other
entity points at this one (e.g. host:hubris —hosts→ lxc:sophia) unless
that other entity happened to also be reachable going forward from
here. The Outgoing/Incoming split was filtering correctly, but
"Incoming" was starved of data by construction.

Switch to GET /entities/{id}/relations?direction=both — a dedicated
endpoint that matches on source_id OR target_id directly — via a new
fetchEntityRelations(). Simplifies the incoming/outgoing derivation
too, since every relation returned is now actually incident to the
entity (no more sibling-edge filtering needed).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/lib/api.ts

@@ -494,6 +494,18 @@ export interface Relationship {
   valid_to?: string | null
 }
 
+// Direct relationships of an entity, both directions — unlike fetchGraph's
+// blast_radius (which only walks outgoing edges, so it can never surface an
+// edge some other entity points at this one unless that entity is also
+// reachable going forward from here), this hits a dedicated endpoint that
+// matches on source_id OR target_id directly.
+export async function fetchEntityRelations(id: string): Promise<Relationship[]> {
+  const res = await fetchWithAuth(`${API}/entities/${encodeURIComponent(id)}/relations?direction=both`)
+  if (!res.ok) return []
+  const data = await res.json()
+  return data.items ?? []
+}
+
 export type Health = 'healthy' | 'degraded' | 'down' | 'unknown'
 
 export interface GraphView {