feat(web): unify Knowledge Base filtering into one type multiselect

Replace the Fleet/Network/Identity/Knowledge category tabs (which
scoped entity fetches server-side) with a single "Types" multiselect
shared by both the table and graph views — both now fetch the whole
entity set (paginated via the new fetchAllEntities) and filter
client-side, defaulting to fleet's types. Table and graph also share
one search/highlight field instead of two separately-labeled ones.

Along the way, fixed a real bug the wider entity set exposed: the
treegrid's parent/child grouping fired one fetchGraph call per
candidate root entity, fine for the old ~50-entity fleet scope but an
ERR_INSUFFICIENT_RESOURCES flood once scoped to the full ~1700-entity
set. Replaced with a single whole-graph fetch, deriving parent/child
pairs from its edges client-side.

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

web/src/lib/api.ts

@@ -213,6 +213,24 @@ export async function fetchEntities(filters: EntityFilters = {}): Promise<Entity
   return data.items ?? []
 }
 
+// The entities endpoint caps at 200/page — the Knowledge Base wants the
+// whole set (it filters by type/search client-side now instead of scoping
+// the fetch server-side), so page through via cursor until exhausted.
+export async function fetchAllEntities(): Promise<Entity[]> {
+  const all: Entity[] = []
+  let cursor: string | undefined
+  do {
+    const params = new URLSearchParams({ limit: '200' })
+    if (cursor) params.set('cursor', cursor)
+    const res = await fetchWithAuth(`${API}/entities?${params}`)
+    if (!res.ok) break
+    const data = await res.json()
+    all.push(...(data.items ?? []))
+    cursor = data.next_cursor ?? undefined
+  } while (cursor)
+  return all
+}
+
 export type OntologyLayer = 'meta' | 'infrastructure' | 'governance' | 'cognition'
 
 export interface EntityType {