feat(web): browse Knowledge Base by mixed Network/Fleet/Services/Storage/Identity/Knowledge categories

Replace the layer-based (Infrastructure/Governance/Cognition) browsing tabs
with a synthesized category taxonomy built from the ontology's finer-grained
`domain` field, since layer lumped unrelated entity types (an LXC and a DNS
record and a storage volume) into one bucket. Network and Fleet each span
two domains, so the table view now fans out per-domain fetches and merges,
while the graph view maps domain->category client-side. Also carries over
several detail-panel polish items (Tasks-not-raw-executions, slug URL
encoding, MultiSelectFilter) from earlier in this session.

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

web/src/lib/utils.ts

@@ -21,6 +21,16 @@ export function relativeTime(iso: string | null | undefined): string {
 	return `${d}d ago`;
 }
 
+// Truncates long slugs/names in the middle (keeping the "type:" prefix and
+// the tail visible) rather than at the end — for slugs the distinguishing
+// part is often at both ends, e.g. "investigation:nomos/dragonfly-memlock-…"
+// vs "…rlimit-type-8-in-unprivileged-lxcs".
+export function truncateMiddle(s: string, maxLen = 36): string {
+	if (s.length <= maxLen) return s;
+	const keep = Math.floor((maxLen - 1) / 2);
+	return `${s.slice(0, keep)}…${s.slice(-keep)}`;
+}
+
 // debounce wraps fn so rapid calls (e.g. keystrokes in a filter input)
 // collapse into one invocation after `wait`ms of silence.
 export function debounce<T extends (...args: never[]) => void>(fn: T, wait = 300): T {