refactor(ui): make the two job pollers declarative, and finish the container tabs

Plan 76 milestone E2, continuing 89c3896e. Ratchet 22 sites / 15 files -> 16 / 12.

DoctorPanel's fleet sweep and ScannerTab's malware scan were imperative
pollers: a function started an interval, and the interval cleared itself once
the job reached a terminal status, with a second clearInterval in an unmount
cleanup to catch the case where it never did. Both now hold the job id in state
and let usePolling own the schedule —

    const pollSweep = useCallback((jobId) => setSweepJobId(jobId), []);
    usePolling(tick, SWEEP_POLL_MS, { enabled: Boolean(sweepJobId) });

which is what makes the visibility pause and the in-flight guard apply to them
too. A job poller is the shape that most wants both: it runs while someone
watches a spinner, and its endpoint is doing real work.

Also ContainersTab's stats poll and log tail, and OnboardingWizard's status
poll (its 1s elapsed-time clock stays a plain interval — nothing to overlap).

Two `useRef`s and one `clearInterval` in an unmount cleanup went with them.

Gate: npm run build clean, npm run lint 0 errors / 953 warnings, npm test 72
passed, boundary check green.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

frontend/scripts/check-frontend-boundaries.mjs

@@ -45,10 +45,7 @@ const LEGACY_CLIPBOARD = new Map();
 const LEGACY_POLLERS = new Map(Object.entries({
     'components/dashboard/widgets/renderers.jsx': 1,
     'components/deploy-console/SuccessBanner.jsx': 1,
-    'components/docker/ContainersTab.jsx': 2,
-    'components/monitoring/DoctorPanel.jsx': 1,
-    'components/security/ScannerTab.jsx': 2,
-    'components/server/OnboardingWizard.jsx': 2,
+    'components/server/OnboardingWizard.jsx': 1,
     'hooks/useContainerStatus.js': 1,
     'hooks/useDeployJobStream.js': 1,
     'hooks/useMetrics.js': 1,

frontend/src/components/docker/ContainersTab.jsx

@@ -41,6 +41,13 @@ import {
 import { ContainerResourceBars } from './dockerShared';
 import { copyToClipboard } from '@/utils/clipboard';
 import { downloadBlob } from '@/utils/downloadBlob';
+import { usePolling } from '@/hooks/usePolling';
+
+// Container stats cadence.
+const STATS_REFRESH_MS = 10000;
+// Container log tail cadence while auto-refresh is on.
+const LOG_TAIL_MS = 3000;
+
 
 // Action Buttons
 export const RunContainerButton = () => {
@@ -284,15 +291,11 @@ const ContainersTab = ({ onStatsChange }) => {
         }));
     }, [fetchContainerStats, isRemote]);
 
-    useEffect(() => {
-        if (loading || containers.length === 0) return undefined;
-
-        const timer = window.setInterval(() => {
-            refreshContainerStats(containers, statsRequestSeq.current);
-        }, 10000);
-
-        return () => window.clearInterval(timer);
-    }, [containers, loading, refreshContainerStats]);
+    usePolling(
+        () => refreshContainerStats(containers, statsRequestSeq.current),
+        STATS_REFRESH_MS,
+        { enabled: !loading && containers.length > 0, immediate: false },
+    );
 
     async function loadContainers() {
         setLoading(true);
@@ -1225,18 +1228,15 @@ const ContainerLogsModal = ({ container, onClose }) => {
     const [showLineNumbers, setShowLineNumbers] = useState(true);
     const [wrapLines, setWrapLines] = useState(true);
     const contentRef = useRef(null);
-    const intervalRef = useRef(null);
 
     useEffect(() => {
         loadLogs();
     }, [container, tail]); // eslint-disable-line
 
-    useEffect(() => {
-        if (autoRefresh) {
-            intervalRef.current = setInterval(() => loadLogs(false), 3000);
-        }
-        return () => { if (intervalRef.current) clearInterval(intervalRef.current); };
-    }, [autoRefresh, tail]); // eslint-disable-line
+    usePolling(() => loadLogs(false), LOG_TAIL_MS, {
+        enabled: autoRefresh,
+        immediate: false,
+    });
 
     async function loadLogs(showSpinner = true) {
         if (showSpinner) setLoading(true);

frontend/src/components/monitoring/DoctorPanel.jsx

@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useRef, useState } from 'react';
+import { useCallback, useEffect, useState } from 'react';
 import { useNavigate } from 'react-router-dom';
 import api from '../../services/api';
 import { useToast } from '../../contexts/ToastContext';
@@ -7,6 +7,7 @@ import Modal from '@/components/Modal';
 import { Pill } from '@/components/ds';
 import EmptyState from '../EmptyState';
 import { ChevronDown, ChevronRight, Server, Stethoscope, Wrench } from 'lucide-react';
+import { usePolling } from '@/hooks/usePolling';
 
 const STATUS_TONE = { ok: 'green', warn: 'amber', fail: 'red', error: 'red' };
 
@@ -73,7 +74,7 @@ const DoctorPanel = () => {
     const [fleet, setFleet] = useState(null);
     const [fleetLoading, setFleetLoading] = useState(true);
     const [sweeping, setSweeping] = useState(false);
-    const sweepPollRef = useRef(null);
+    const [sweepJobId, setSweepJobId] = useState(null);
 
     const loadFleet = useCallback(async () => {
         try {
@@ -94,10 +95,7 @@ const DoctorPanel = () => {
             .catch(() => { /* no stored report yet — the empty state covers it */ })
             .finally(() => { if (!cancelled) setLoading(false); });
         loadFleet();
-        return () => {
-            cancelled = true;
-            if (sweepPollRef.current) clearInterval(sweepPollRef.current);
-        };
+        return () => { cancelled = true; };
     }, [loadFleet]);
 
     const runDiagnosis = async () => {
@@ -116,27 +114,27 @@ const DoctorPanel = () => {
         }
     };
 
-    const pollSweep = useCallback((jobId) => {
-        if (sweepPollRef.current) clearInterval(sweepPollRef.current);
-        sweepPollRef.current = setInterval(async () => {
-            try {
-                const res = await api.getJob(jobId);
-                const job = res.job || res;
-                if (!TERMINAL_JOB_STATUSES.includes(job.status)) return;
-                clearInterval(sweepPollRef.current);
-                sweepPollRef.current = null;
-                setSweeping(false);
-                if (job.status === 'succeeded') {
-                    await loadFleet();
-                    toast.success('Fleet sweep finished');
-                } else {
-                    toast.error(job.error_message || 'Fleet sweep did not finish');
-                }
-            } catch {
-                // Transient poll failure — the next tick retries.
+    // The job id IS the "are we polling" state, so the poll is declarative and
+    // the hook owns starting, stopping, and not overlapping ticks.
+    const pollSweep = useCallback((jobId) => setSweepJobId(jobId), []);
+
+    usePolling(async () => {
+        try {
+            const res = await api.getJob(sweepJobId);
+            const job = res.job || res;
+            if (!TERMINAL_JOB_STATUSES.includes(job.status)) return;
+            setSweepJobId(null);
+            setSweeping(false);
+            if (job.status === 'succeeded') {
+                await loadFleet();
+                toast.success('Fleet sweep finished');
+            } else {
+                toast.error(job.error_message || 'Fleet sweep did not finish');
             }
-        }, SWEEP_POLL_MS);
-    }, [loadFleet, toast]);
+        } catch {
+            // Transient poll failure — the next tick retries.
+        }
+    }, SWEEP_POLL_MS, { enabled: Boolean(sweepJobId), immediate: false });
 
     const runSweep = async () => {
         try {

frontend/src/components/security/ScannerTab.jsx

@@ -12,6 +12,11 @@ import { useColumnVisibility } from '@/hooks/useColumnVisibility';
 import { Zap, Radar, FolderSearch, Download, Box, FileCode2, Trash2, Search } from 'lucide-react';
 import EmptyState from '@/components/EmptyState';
 import { useConfirm } from '@/hooks/useConfirm';
+import { usePolling } from '@/hooks/usePolling';
+
+// Scan status cadence, and the faster cadence while a scan job runs.
+const SCAN_STATUS_POLL_MS = 5000;
+const SCAN_JOB_POLL_MS = 3000;
 
 const SEVERITY_TONE = {
     critical: 'red',
@@ -135,7 +140,7 @@ const ScannerTab = () => {
     const [apps, setApps] = useState([]);
     const [selectedApp, setSelectedApp] = useState('');
     const [scanJob, setScanJob] = useState(null); // { id, status, result }
-    const jobPollRef = useRef(null);
+    const [scanJobId, setScanJobId] = useState(null);
 
     // Findings (YARA + ClamAV) from the last completed job/scan
     const [findings, setFindings] = useState([]);
@@ -155,13 +160,10 @@ const ScannerTab = () => {
         loadScanStatus();
         loadHistory();
         loadApps();
-        const interval = setInterval(loadScanStatus, 5000);
-        return () => {
-            clearInterval(interval);
-            if (jobPollRef.current) clearInterval(jobPollRef.current);
-        };
     }, []);
 
+    usePolling(loadScanStatus, SCAN_STATUS_POLL_MS, { immediate: false });
+
     async function loadScanStatus() {
         try {
             const data = await api.getScanStatus();
@@ -201,36 +203,37 @@ const ScannerTab = () => {
         }
     }
 
+    // The job id IS the "are we polling" state; the hook owns the schedule,
+    // so this only has to say which job to watch.
     function pollJob(jobId) {
-        if (jobPollRef.current) clearInterval(jobPollRef.current);
-        jobPollRef.current = setInterval(async () => {
-            try {
-                const job = await api.getJob(jobId);
-                setScanJob(job);
-                if (['succeeded', 'failed', 'cancelled'].includes(job.status)) {
-                    clearInterval(jobPollRef.current);
-                    jobPollRef.current = null;
-                    if (job.status === 'succeeded' && job.result?.findings) {
-                        setFindings(job.result.findings);
-                        const n = job.result.findings.length;
-                        setMessage({
-                            type: n > 0 ? 'error' : 'success',
-                            text: n > 0
-                                ? `Scan finished: ${n} finding(s) — review below`
-                                : 'Scan finished: no threats found'
-                        });
-                    } else if (job.status === 'failed') {
-                        setMessage({ type: 'error', text: job.error_message || 'Scan job failed' });
-                    }
-                    loadScanStatus();
-                    loadHistory();
-                }
-            } catch (err) {
-                console.error('Failed to poll scan job:', err);
-            }
-        }, 3000);
+        setScanJobId(jobId);
     }
 
+    usePolling(async () => {
+        try {
+            const job = await api.getJob(scanJobId);
+            setScanJob(job);
+            if (!['succeeded', 'failed', 'cancelled'].includes(job.status)) return;
+            setScanJobId(null);
+            if (job.status === 'succeeded' && job.result?.findings) {
+                setFindings(job.result.findings);
+                const n = job.result.findings.length;
+                setMessage({
+                    type: n > 0 ? 'error' : 'success',
+                    text: n > 0
+                        ? `Scan finished: ${n} finding(s) — review below`
+                        : 'Scan finished: no threats found',
+                });
+            } else if (job.status === 'failed') {
+                setMessage({ type: 'error', text: job.error_message || 'Scan job failed' });
+            }
+            loadScanStatus();
+            loadHistory();
+        } catch (err) {
+            console.error('Failed to poll scan job:', err);
+        }
+    }, SCAN_JOB_POLL_MS, { enabled: Boolean(scanJobId), immediate: false });
+
     async function handleScanApp() {
         if (!selectedApp) return;
         setScanning(true);

frontend/src/components/server/OnboardingWizard.jsx

@@ -4,6 +4,11 @@ import { useToast } from '../../contexts/ToastContext';
 import { Button } from '@/components/ui/button';
 import { Pill } from '../ds';
 import { CheckCircle2, Loader2, Circle, XCircle, RotateCw, Clock, ChevronDown } from 'lucide-react';
+import { usePolling } from '@/hooks/usePolling';
+
+// Onboarding status cadence while non-terminal.
+const ONBOARDING_POLL_MS = 3000;
+
 
 // The canonical ordered lifecycle steps. The backend returns the same list in
 // `status.states`, but we keep a labeled copy so the wizard renders before the
@@ -109,12 +114,10 @@ const OnboardingWizard = ({ serverId, initialState, onStateChange }) => {
     }, [loadStatus]);
 
     // Poll while onboarding is in flight; stop once terminal.
-    useEffect(() => {
-        if (!status) return undefined;
-        if (status.is_terminal) return undefined;
-        const interval = setInterval(loadStatus, 3000);
-        return () => clearInterval(interval);
-    }, [status, loadStatus]);
+    usePolling(loadStatus, ONBOARDING_POLL_MS, {
+        enabled: Boolean(status) && !status.is_terminal,
+        immediate: false,
+    });
 
     // Keep the elapsed timer ticking only while non-terminal.
     useEffect(() => {