fix(tasks): eliminate duplicate task entries by stabilizing WS listener and deduplicating task state

frontend/src/App.tsx

@@ -208,7 +208,7 @@ export const App: React.FC = () => {
     } else {
       disconnectWebSocket();
     }
-  }, [user]);
+  }, [user?.id]);
 
   // Refresh stats on task/doc real-time events
   useEffect(() => {
@@ -253,7 +253,10 @@ export const App: React.FC = () => {
     target: 'inbox' | 'task' | 'list_item' | 'document' = 'inbox'
   ) => {
     if (target === 'inbox' && thought.status === 'inbox') {
-      setDeck((prev) => [thought, ...prev]);
+      setDeck((prev) => {
+        if (prev.some((t) => t.id === thought.id)) return prev;
+        return [thought, ...prev];
+      });
       setStats((prev) => ({ ...prev, inboxCount: prev.inboxCount + 1 }));
     } else if (target === 'document' && thought.convertedRefId) {
       setSelectedDocId(thought.convertedRefId);

frontend/src/features/triage/TasksView.tsx

@@ -1,4 +1,4 @@
-import React, { useEffect, useState } from 'react';
+import React, { useEffect, useState, useRef, useMemo } from 'react';
 import {
   Check,
   Plus,
@@ -96,7 +96,16 @@ export const TasksView: React.FC<TasksViewProps> = ({
     loadData();
   }, [refreshTrigger, selectedListId]);
 
-  // Live-Sync WebSocket listener for tasks
+  const selectedListIdRef = useRef(selectedListId);
+  selectedListIdRef.current = selectedListId;
+
+  const activeNotesTaskIdRef = useRef(activeNotesTaskId);
+  activeNotesTaskIdRef.current = activeNotesTaskId;
+
+  const onRefreshStatsRef = useRef(onRefreshStats);
+  onRefreshStatsRef.current = onRefreshStats;
+
+  // Live-Sync WebSocket listener for tasks (registered once on mount)
   useEffect(() => {
     const handleWs = (e: any) => {
       const msg = e.detail;
@@ -113,10 +122,10 @@ export const TasksView: React.FC<TasksViewProps> = ({
         ) {
           setTasks((prev) => {
             if (prev.some((t) => t.id === created.id)) return prev;
-            if (selectedListId !== 'all' && created.taskListId !== selectedListId) return prev;
+            if (selectedListIdRef.current !== 'all' && created.taskListId !== selectedListIdRef.current) return prev;
             return [created, ...prev];
           });
-          onRefreshStats();
+          onRefreshStatsRef.current();
         }
       } else if (msg.event === 'TASK_UPDATED') {
         const updated = msg.payload as Thought;
@@ -129,37 +138,37 @@ export const TasksView: React.FC<TasksViewProps> = ({
                   updated.kanbanStatus ||
                   updated.taskListId ||
                   updated.isCompleted !== undefined) &&
-                (selectedListId === 'all' || updated.taskListId === selectedListId)
+                (selectedListIdRef.current === 'all' || updated.taskListId === selectedListIdRef.current)
               ) {
                 return [updated, ...prev];
               }
               return prev;
             }
-            if (selectedListId !== 'all' && updated.taskListId !== selectedListId) {
+            if (selectedListIdRef.current !== 'all' && updated.taskListId !== selectedListIdRef.current) {
               return prev.filter((t) => t.id !== updated.id);
             }
             return prev.map((t) => {
               if (t.id !== updated.id) return t;
               return {
                 ...updated,
-                notes: activeNotesTaskId === updated.id ? t.notes : updated.notes,
+                notes: activeNotesTaskIdRef.current === updated.id ? t.notes : updated.notes,
               };
             });
           });
-          onRefreshStats();
+          onRefreshStatsRef.current();
         }
       } else if (msg.event === 'TASK_DELETED') {
         const deletedId = typeof msg.payload === 'string' ? msg.payload : msg.payload?.id;
         if (deletedId) {
           setTasks((prev) => prev.filter((t) => t.id !== deletedId));
-          onRefreshStats();
+          onRefreshStatsRef.current();
         }
       }
     };
 
     window.addEventListener('mindsift:ws', handleWs);
     return () => window.removeEventListener('mindsift:ws', handleWs);
-  }, [selectedListId, activeNotesTaskId, onRefreshStats]);
+  }, []);
 
   const handleToggleDone = async (task: Thought) => {
     triggerHaptic(15);
@@ -400,7 +409,10 @@ export const TasksView: React.FC<TasksViewProps> = ({
         target: 'task',
         taskListId: selectedListId === 'all' ? '' : selectedListId,
       });
-      setTasks((prev) => [created, ...prev]);
+      setTasks((prev) => {
+        if (prev.some((t) => t.id === created.id)) return prev;
+        return [created, ...prev];
+      });
       onRefreshStats();
     } catch {
       loadData();
@@ -466,7 +478,18 @@ export const TasksView: React.FC<TasksViewProps> = ({
     }
   };
 
-  const safeTasks = Array.isArray(tasks) ? tasks : [];
+  const safeTasks = useMemo(() => {
+    if (!Array.isArray(tasks)) return [];
+    const seen = new Set<string>();
+    const unique: Thought[] = [];
+    for (const t of tasks) {
+      if (t && t.id && !seen.has(t.id)) {
+        seen.add(t.id);
+        unique.push(t);
+      }
+    }
+    return unique;
+  }, [tasks]);
   const safeTaskLists = Array.isArray(taskLists) ? taskLists : [];
   const safeSpaces = Array.isArray(spaces) ? spaces : [];
   const safeDiscarded = Array.isArray(discarded) ? discarded : [];