Add AbortController cleanup to async frontend effects

frontend/src/components/blocklist/BlocklistScheduleSection.tsx

@@ -1,4 +1,4 @@
-import { useCallback, useState } from "react";
+import { useCallback, useEffect, useRef, useState } from "react";
 import { Button, Field, Input, MessageBar, MessageBarBody, Select, Spinner, Text } from "@fluentui/react-components";
 import { PlayRegular } from "@fluentui/react-icons";
 import { useCommonSectionStyles } from "../../theme/commonStyles";
@@ -25,6 +25,7 @@ export function BlocklistScheduleSection({ onRunImport, runImportRunning }: Sche
   const { info, loading, error, saveSchedule } = useSchedule();
   const [saving, setSaving] = useState(false);
   const [saveMsg, setSaveMsg] = useState<string | null>(null);
+  const saveTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
 
   const config = info?.config ?? {
     frequency: "daily" as ScheduleFrequency,
@@ -37,12 +38,20 @@ export function BlocklistScheduleSection({ onRunImport, runImportRunning }: Sche
   const [draft, setDraft] = useState<ScheduleConfig>(config);
 
   const handleSave = useCallback((): void => {
+    if (saveTimeoutRef.current) {
+      clearTimeout(saveTimeoutRef.current);
+      saveTimeoutRef.current = null;
+    }
+
     setSaving(true);
     saveSchedule(draft)
       .then(() => {
         setSaveMsg("Schedule saved.");
         setSaving(false);
-        setTimeout(() => { setSaveMsg(null); }, 3000);
+        saveTimeoutRef.current = setTimeout(() => {
+          setSaveMsg(null);
+          saveTimeoutRef.current = null;
+        }, 3000);
       })
       .catch((err: unknown) => {
         setSaveMsg(err instanceof Error ? err.message : "Failed to save schedule");
@@ -50,6 +59,14 @@ export function BlocklistScheduleSection({ onRunImport, runImportRunning }: Sche
       });
   }, [draft, saveSchedule]);
 
+  useEffect(() => {
+    return (): void => {
+      if (saveTimeoutRef.current) {
+        clearTimeout(saveTimeoutRef.current);
+      }
+    };
+  }, []);
+
   return (
     <div className={sectionStyles.section}>
       <div className={sectionStyles.sectionHeader}>

frontend/src/components/config/ActivateJailDialog.tsx

@@ -106,12 +106,14 @@ export function ActivateJailDialog({
   useEffect(() => {
     if (!open || !jail) return;
 
+    const controller = new AbortController();
     setValidating(true);
     setValidationIssues([]);
     setValidationWarnings([]);
 
     onValidate()
       .then((result) => {
+        if (controller.signal.aborted) return;
         setValidationIssues(result.issues);
       })
       .catch(() => {
@@ -119,8 +121,13 @@ export function ActivateJailDialog({
         // attempt activation and let the server decide.
       })
       .finally(() => {
+        if (controller.signal.aborted) return;
         setValidating(false);
       });
+
+    return (): void => {
+      controller.abort();
+    };
   }, [open, jail, onValidate]);
 
   const handleClose = (): void => {

frontend/src/components/config/ConfFilesTab.tsx

@@ -75,25 +75,33 @@ export function ConfFilesTab({
   const [newContent, setNewContent] = useState("");
   const [creating, setCreating] = useState(false);
 
-  const loadFiles = useCallback(async () => {
+  const loadFiles = useCallback(async (signal?: AbortSignal) => {
     setLoading(true);
     setError(null);
     try {
       const resp = await fetchList();
+      if (signal?.aborted) return;
       setFiles(resp.files);
     } catch (err: unknown) {
+      if (signal?.aborted) return;
       setError(
         err instanceof ApiError
           ? err.message
           : `Failed to load ${label.toLowerCase()} files.`,
       );
     } finally {
-      setLoading(false);
+      if (!signal?.aborted) {
+        setLoading(false);
+      }
     }
   }, [fetchList, label]);
 
   useEffect(() => {
-    void loadFiles();
+    const controller = new AbortController();
+    void loadFiles(controller.signal);
+    return (): void => {
+      controller.abort();
+    };
   }, [loadFiles]);
 
   const handleAccordionToggle = useCallback(