Consolidate toast effects, extract useConfirmAction, extend index

- W3: Merge route-change and new-alert effects into single unified effect
- W6: Migration 018 extends due_lookup index with snoozed_until column
- S1: Extract useConfirmAction hook from TodoItem/ReminderItem
- S7: Update summary toast count on dismiss/snooze instead of dismissing

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/alembic/versions/018_extend_due_lookup_index.py

@@ -0,0 +1,33 @@
+"""Extend due lookup index to include snoozed_until
+
+Revision ID: 018
+Revises: 017
+Create Date: 2026-02-24
+
+"""
+from alembic import op
+
+
+# revision identifiers, used by Alembic.
+revision = "018"
+down_revision = "017"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.drop_index("ix_reminders_due_lookup", table_name="reminders")
+    op.create_index(
+        "ix_reminders_due_lookup",
+        "reminders",
+        ["is_active", "is_dismissed", "remind_at", "snoozed_until"],
+    )
+
+
+def downgrade() -> None:
+    op.drop_index("ix_reminders_due_lookup", table_name="reminders")
+    op.create_index(
+        "ix_reminders_due_lookup",
+        "reminders",
+        ["is_active", "is_dismissed", "remind_at"],
+    )

frontend/src/components/reminders/ReminderItem.tsx

@@ -1,4 +1,4 @@
-import { useState, useRef, useEffect } from 'react';
+import { useCallback } from 'react';
 import { useMutation, useQueryClient } from '@tanstack/react-query';
 import { toast } from 'sonner';
 import { Bell, BellOff, Trash2, Pencil } from 'lucide-react';
@@ -7,6 +7,7 @@ import api from '@/lib/api';
 import type { Reminder } from '@/types';
 import { cn } from '@/lib/utils';
 import { Button } from '@/components/ui/button';
+import { useConfirmAction } from '@/hooks/useConfirmAction';
 
 interface ReminderItemProps {
   reminder: Reminder;
@@ -23,9 +24,6 @@ const QUERY_KEYS = [['reminders'], ['dashboard'], ['upcoming']] as const;
 
 export default function ReminderItem({ reminder, onEdit }: ReminderItemProps) {
   const queryClient = useQueryClient();
-  const [confirmingDelete, setConfirmingDelete] = useState(false);
-  const deleteTimerRef = useRef<ReturnType<typeof setTimeout>>();
-  useEffect(() => () => clearTimeout(deleteTimerRef.current), []);
 
   const remindDate = reminder.remind_at ? parseISO(reminder.remind_at) : null;
   const isOverdue = !reminder.is_dismissed && remindDate && isPast(remindDate) && !isToday(remindDate);
@@ -69,16 +67,8 @@ export default function ReminderItem({ reminder, onEdit }: ReminderItemProps) {
     },
   });
 
-  const handleDelete = () => {
-    if (!confirmingDelete) {
-      setConfirmingDelete(true);
-      deleteTimerRef.current = setTimeout(() => setConfirmingDelete(false), 4000);
-      return;
-    }
-    clearTimeout(deleteTimerRef.current);
-    deleteMutation.mutate();
-    setConfirmingDelete(false);
-  };
+  const executeDelete = useCallback(() => deleteMutation.mutate(), [deleteMutation]);
+  const { confirming: confirmingDelete, handleClick: handleDelete } = useConfirmAction(executeDelete);
 
   return (
     <div

frontend/src/components/todos/TodoItem.tsx

@@ -1,4 +1,4 @@
-import { useState, useRef, useEffect } from 'react';
+import { useCallback } from 'react';
 import { useMutation, useQueryClient } from '@tanstack/react-query';
 import { toast } from 'sonner';
 import { Trash2, Pencil, Calendar, Clock, AlertCircle, RefreshCw } from 'lucide-react';
@@ -8,6 +8,7 @@ import type { Todo } from '@/types';
 import { cn, isTodoOverdue } from '@/lib/utils';
 import { Checkbox } from '@/components/ui/checkbox';
 import { Button } from '@/components/ui/button';
+import { useConfirmAction } from '@/hooks/useConfirmAction';
 
 interface TodoItemProps {
   todo: Todo;
@@ -31,9 +32,6 @@ const QUERY_KEYS = [['todos'], ['dashboard'], ['upcoming']] as const;
 
 export default function TodoItem({ todo, onEdit }: TodoItemProps) {
   const queryClient = useQueryClient();
-  const [confirmingDelete, setConfirmingDelete] = useState(false);
-  const deleteTimerRef = useRef<ReturnType<typeof setTimeout>>();
-  useEffect(() => () => clearTimeout(deleteTimerRef.current), []);
 
   const toggleMutation = useMutation({
     mutationFn: async () => {
@@ -75,16 +73,8 @@ export default function TodoItem({ todo, onEdit }: TodoItemProps) {
     },
   });
 
-  const handleDelete = () => {
-    if (!confirmingDelete) {
-      setConfirmingDelete(true);
-      deleteTimerRef.current = setTimeout(() => setConfirmingDelete(false), 4000);
-      return;
-    }
-    clearTimeout(deleteTimerRef.current);
-    deleteMutation.mutate();
-    setConfirmingDelete(false);
-  };
+  const executeDelete = useCallback(() => deleteMutation.mutate(), [deleteMutation]);
+  const { confirming: confirmingDelete, handleClick: handleDelete } = useConfirmAction(executeDelete);
 
   const dueDate = todo.due_date ? parseISO(todo.due_date) : null;
   const isDueToday = dueDate ? isToday(dueDate) : false;

frontend/src/hooks/useAlerts.tsx

@@ -83,19 +83,33 @@ export function AlertsProvider({ children }: { children: ReactNode }) {
     },
   });
 
+  const updateSummaryToast = useCallback(() => {
+    // Count alerts that are still fired but don't have individual toasts (overflow)
+    const totalFired = firedRef.current.size;
+    const overflow = totalFired - MAX_TOASTS;
+    if (overflow > 0) {
+      toast.custom(
+        (t) => renderSummaryToast(t, overflow),
+        { id: 'reminder-summary', duration: Infinity }
+      );
+    } else {
+      toast.dismiss('reminder-summary');
+    }
+  }, []);
+
   const handleDismiss = useCallback((id: number) => {
     toast.dismiss(`reminder-${id}`);
-    toast.dismiss('reminder-summary');
     firedRef.current.delete(id);
+    updateSummaryToast();
     dismissMutation.mutate(id);
-  }, [dismissMutation]);
+  }, [dismissMutation, updateSummaryToast]);
 
   const handleSnooze = useCallback((id: number, minutes: 5 | 10 | 15) => {
     toast.dismiss(`reminder-${id}`);
-    toast.dismiss('reminder-summary');
     firedRef.current.delete(id);
+    updateSummaryToast();
     snoozeMutation.mutate({ id, minutes });
-  }, [snoozeMutation]);
+  }, [snoozeMutation, updateSummaryToast]);
 
   // Store latest callbacks in refs so toast closures always call current versions
   const dismissRef = useRef(handleDismiss);
@@ -172,29 +186,28 @@ export function AlertsProvider({ children }: { children: ReactNode }) {
     }
   }
 
-  // Handle route changes
+  // Unified toast management — single effect handles both route changes and new alerts
   useEffect(() => {
     const wasOnDashboard = prevPathnameRef.current === '/' || prevPathnameRef.current === '/dashboard';
     const nowOnDashboard = isDashboard;
     prevPathnameRef.current = location.pathname;
 
     if (nowOnDashboard) {
-      // Moving TO dashboard — dismiss all toasts, banner takes over
+      // On dashboard — dismiss all toasts, banner takes over
       alerts.forEach((a) => toast.dismiss(`reminder-${a.id}`));
       toast.dismiss('reminder-summary');
       firedRef.current.clear();
-    } else if (wasOnDashboard && !nowOnDashboard) {
-      // Moving AWAY from dashboard — fire toasts for current alerts
-      firedRef.current.clear();
-      fireToasts(alerts);
+      return;
     }
-  }, [location.pathname, isDashboard, alerts]);
 
-  // Fire toasts for new alerts on non-dashboard pages
-  useEffect(() => {
-    if (isDashboard) return;
+    // Transitioning away from dashboard — reset fired set so all current alerts get toasts
+    if (wasOnDashboard && !nowOnDashboard) {
+      firedRef.current.clear();
+    }
+
+    // On non-dashboard page — fire toasts for any unfired alerts
     fireToasts(alerts);
-  }, [alerts, isDashboard]);
+  }, [location.pathname, isDashboard, alerts]);
 
   return (
     <AlertsContext.Provider value={{ alerts, dismiss: handleDismiss, snooze: handleSnooze }}>

frontend/src/hooks/useConfirmAction.ts

@@ -0,0 +1,26 @@
+import { useState, useRef, useEffect, useCallback } from 'react';
+
+/**
+ * Two-click confirmation pattern: first click shows "Sure?", second executes.
+ * Auto-resets after `timeoutMs` if the user doesn't confirm.
+ * Cleans up the timer on unmount.
+ */
+export function useConfirmAction(action: () => void, timeoutMs = 4000) {
+  const [confirming, setConfirming] = useState(false);
+  const timerRef = useRef<ReturnType<typeof setTimeout>>();
+
+  useEffect(() => () => clearTimeout(timerRef.current), []);
+
+  const handleClick = useCallback(() => {
+    if (!confirming) {
+      setConfirming(true);
+      timerRef.current = setTimeout(() => setConfirming(false), timeoutMs);
+      return;
+    }
+    clearTimeout(timerRef.current);
+    action();
+    setConfirming(false);
+  }, [confirming, action, timeoutMs]);
+
+  return { confirming, handleClick };
+}