Add L0-L4 security clearance for fleet commands and AI elevation.

Gate manual and AI commands by per-agent clearance, auto-elevate stuck hosts to L4 when AI mode allows, and surface clearance in Access Depth and LOTL timeline.

server/web/src/api/client.ts

@@ -230,6 +230,14 @@ export const api = {
     params.set('limit', String(limit));
     return fetchJSON<AIDecisionRecord[]>(`/ai/decisions?${params}`);
   },
+  getClearanceEvents: (agentId?: string, limit = 50) => {
+    const params = new URLSearchParams();
+    if (agentId?.trim()) params.set('agent_id', agentId.trim());
+    params.set('limit', String(limit));
+    return fetchJSON<import('../help/clearance').ClearanceEventRecord[]>(
+      `/ai/clearance-events?${params}`,
+    );
+  },
   getAIModels: (endpoint: string) =>
     fetchJSON<{ models: string[]; endpoint?: string; error?: string }>(
       `/ai/models?endpoint=${encodeURIComponent(endpoint)}`,