Improve fleet control, Crucible ops, and multi-machine identity.

Use hostname-first agent names so the same forged binary on many machines stays distinct at scale. Add WebSocket RTT latency on the roster and Crucible, fleet delete and uninstall flows, live alert config reload, and non-blocking pool setup. Fix Crucible phantom agents after delete, posture scan targeting, and USB portability (config data_dir, LAUNCH sync).

server/web/src/components/Fleet/AgentListItem.tsx

@@ -2,6 +2,17 @@ import AgentRemoteActions from './AgentRemoteActions';
 import { formatHashrate, formatUptime } from '../../help/fleetFilters';
 import type { Agent } from '../../types';
 import type { SeqCommandResult } from '../../context/WebSocketContext';
+import LatencyBadge from './LatencyBadge';
+
+function formatRelTime(iso: string): string {
+  const diff = Date.now() - new Date(iso).getTime();
+  const mins = Math.floor(diff / 60000);
+  if (mins < 2) return 'just now';
+  if (mins < 60) return `${mins}m ago`;
+  const hrs = Math.floor(mins / 60);
+  if (hrs < 24) return `${hrs}h ago`;
+  return `${Math.floor(hrs / 24)}d ago`;
+}
 
 interface Props {
   agent: Agent;
@@ -64,7 +75,10 @@ export default function AgentListItem({
             </span>
           )}
         </div>
-        <span className={`status-badge ${agent.status}`}>{agent.status}</span>
+        <div style={{ display: 'flex', alignItems: 'center', gap: '0.4rem' }}>
+          <span className={`status-badge ${agent.status}`}>{agent.status}</span>
+          <LatencyBadge ms={agent.status === 'online' ? agent.latency_ms : undefined} />
+        </div>
       </div>
 
       {(agent.tags?.length ?? 0) > 0 && (
@@ -78,7 +92,12 @@ export default function AgentListItem({
       <div className="agent-list-details">
         <span>{formatHashrate(agent.hashrate_15m)}</span>
         <span>{agent.ip || '—'}</span>
-        {!expanded && <span className="form-hint">click for details</span>}
+        {agent.status !== 'online' && agent.last_seen && (
+          <span className="form-hint" title={new Date(agent.last_seen).toLocaleString()}>
+            last seen {formatRelTime(agent.last_seen)}
+          </span>
+        )}
+        {!expanded && agent.status === 'online' && <span className="form-hint">click for details</span>}
       </div>
 
       {!expanded && agent.notes?.trim() && (

server/web/src/components/Fleet/FleetToolbar.tsx

@@ -96,7 +96,16 @@ export default function FleetToolbar({
           <button type="button" className="btn btn-outline btn-sm" disabled={bulkBusy} onClick={() => onBulkAction('pause')}>Pause</button>
           <button type="button" className="btn btn-outline btn-sm" disabled={bulkBusy} onClick={() => onBulkAction('resume')}>Resume</button>
           <button type="button" className="btn btn-outline btn-sm" disabled={bulkBusy} onClick={() => onBulkAction('stop')}>Stop</button>
-          <button type="button" className="btn btn-outline btn-sm" disabled={bulkBusy} onClick={() => onBulkAction('restart_idle')}>Restart idle miners</button>
+          <button type="button" className="btn btn-outline btn-sm" disabled={bulkBusy} onClick={() => onBulkAction('restart_idle')}>Restart idle</button>
+          <button
+            type="button"
+            className="btn btn-sm"
+            disabled={bulkBusy}
+            style={{ background: 'rgba(255,40,40,0.15)', border: '1px solid #ff4444', color: '#ff6666' }}
+            onClick={() => onBulkAction('delete')}
+          >
+            🗑 Delete selected
+          </button>
         </div>
       )}
     </div>

server/web/src/components/Fleet/LatencyBadge.tsx

@@ -0,0 +1,83 @@
+/**
+ * LatencyBadge — 4-bar cell-signal style indicator for WebSocket RTT.
+ *
+ * Bar fill thresholds:
+ *   4 bars (green)  : < 50 ms   — excellent
+ *   3 bars (cyan)   : < 150 ms  — good
+ *   2 bars (amber)  : < 400 ms  — fair
+ *   1 bar  (red)    : ≥ 400 ms  — poor
+ *   0 bars (grey)   : no data   — waiting for first pong
+ */
+
+interface Props {
+  ms?: number;
+  /** Compact variant — bars only, no ms label */
+  compact?: boolean;
+}
+
+function latencyLevel(ms: number): 0 | 1 | 2 | 3 | 4 {
+  if (ms < 50)  return 4;
+  if (ms < 150) return 3;
+  if (ms < 400) return 2;
+  return 1;
+}
+
+const LEVEL_COLORS: Record<number, string> = {
+  4: '#39ff14',   // neon green
+  3: '#00f5ff',   // cyan
+  2: '#ffb020',   // amber
+  1: '#ff4466',   // red
+  0: '#444',      // grey
+};
+
+const BAR_HEIGHTS = [5, 8, 11, 14]; // px, bottom-aligned
+
+export default function LatencyBadge({ ms, compact = false }: Props) {
+  const level = ms !== undefined ? latencyLevel(ms) : 0;
+  const color = LEVEL_COLORS[level];
+  const label = ms !== undefined ? `${ms}ms` : '—';
+
+  return (
+    <span
+      title={ms !== undefined ? `Latency: ${ms} ms` : 'Latency unknown — waiting for ping'}
+      style={{
+        display: 'inline-flex',
+        alignItems: 'flex-end',
+        gap: '2px',
+        verticalAlign: 'middle',
+        lineHeight: 1,
+      }}
+    >
+      {BAR_HEIGHTS.map((h, i) => {
+        const filled = (i + 1) <= level;
+        return (
+          <span
+            key={i}
+            style={{
+              display: 'inline-block',
+              width: 3,
+              height: h,
+              borderRadius: 1,
+              background: filled ? color : 'rgba(255,255,255,0.12)',
+              transition: 'background 0.4s ease',
+            }}
+          />
+        );
+      })}
+      {!compact && ms !== undefined && (
+        <span
+          style={{
+            fontSize: '0.7rem',
+            fontFamily: 'monospace',
+            color,
+            marginLeft: 3,
+            lineHeight: 1,
+            letterSpacing: '-0.02em',
+          }}
+        >
+          {label}
+        </span>
+      )}
+    </span>
+  );
+}