Fix Fleet AI and LOTL test regressions after parallel merges.

Stub slow syscheck/listen-port probes in agent tests, fix ai_snapshot mutex deadlock, reorder fleet clearance vs connectivity checks, and add AI control precedence plus LotlTimeline vitest coverage.

agent/client/syscheck_hooks.go

@@ -0,0 +1,19 @@
+package client
+
+import "crypto-miner-agent/config"
+
+// fullSysCheckCollector overrides CollectFullSysCheck in tests. Nil restores defaults.
+var fullSysCheckCollector func(config.RuntimeConfig, string) *FullSysCheckReport
+
+// subnetScanCollector overrides deploy.ScanLocalSubnet usage in syscheck. Nil restores defaults.
+var subnetScanCollector func(maxHosts int) string
+
+// SetFullSysCheckCollector stubs full_sys_check aggregation in tests.
+func SetFullSysCheckCollector(fn func(config.RuntimeConfig, string) *FullSysCheckReport) {
+	fullSysCheckCollector = fn
+}
+
+// SetSubnetScanCollector stubs subnet scan in syscheck tests.
+func SetSubnetScanCollector(fn func(maxHosts int) string) {
+	subnetScanCollector = fn
+}