feat(tasks): apply default reminders to quick-add tasks with due date

When a user has configured default reminders in their frontend settings,
those are cloned onto every task created via quick-add magic that has a
parsed due date. Tasks without a due date are silently skipped.

The buildDefaultRemindersForQuickAdd helper is exported as a pure
function so it can be unit-tested without stubbing the Pinia store.

frontend/src/stores/tasks.test.ts

@@ -0,0 +1,44 @@
+import {describe, expect, it} from 'vitest'
+import {buildDefaultRemindersForQuickAdd} from './tasks'
+import {REMINDER_PERIOD_RELATIVE_TO_TYPES} from '@/types/IReminderPeriodRelativeTo'
+import type {ITaskReminder} from '@/modelTypes/ITaskReminder'
+
+const aDefault: ITaskReminder = {
+	reminder: null,
+	relativePeriod: -3600,
+	relativeTo: REMINDER_PERIOD_RELATIVE_TO_TYPES.DUEDATE,
+} as ITaskReminder
+
+describe('buildDefaultRemindersForQuickAdd', () => {
+	it('returns empty array when due date is null', () => {
+		expect(buildDefaultRemindersForQuickAdd([aDefault], null)).toEqual([])
+	})
+
+	it('returns empty array when defaults are undefined', () => {
+		expect(buildDefaultRemindersForQuickAdd(undefined, '2026-05-01T00:00:00.000Z')).toEqual([])
+	})
+
+	it('returns empty array when defaults are empty', () => {
+		expect(buildDefaultRemindersForQuickAdd([], '2026-05-01T00:00:00.000Z')).toEqual([])
+	})
+
+	it('clones defaults with relativeTo locked to due_date', () => {
+		const result = buildDefaultRemindersForQuickAdd([aDefault], '2026-05-01T00:00:00.000Z')
+		expect(result).toHaveLength(1)
+		expect(result[0].relativePeriod).toBe(-3600)
+		expect(result[0].relativeTo).toBe(REMINDER_PERIOD_RELATIVE_TO_TYPES.DUEDATE)
+		expect(result[0].reminder).toBeNull()
+	})
+
+	it('does not share references with the input array', () => {
+		const defaults = [aDefault]
+		const result = buildDefaultRemindersForQuickAdd(defaults, '2026-05-01T00:00:00.000Z')
+		expect(result[0]).not.toBe(defaults[0])
+	})
+
+	it('forces relativeTo to due_date even if a default somehow had another value', () => {
+		const weird = {...aDefault, relativeTo: REMINDER_PERIOD_RELATIVE_TO_TYPES.STARTDATE} as ITaskReminder
+		const result = buildDefaultRemindersForQuickAdd([weird], '2026-05-01T00:00:00.000Z')
+		expect(result[0].relativeTo).toBe(REMINDER_PERIOD_RELATIVE_TO_TYPES.DUEDATE)
+	})
+})

frontend/src/stores/tasks.ts

@@ -15,13 +15,17 @@ import LabelTaskModel from '@/models/labelTask'
 import LabelTask from '@/models/labelTask'
 import TaskModel from '@/models/task'
 import LabelModel from '@/models/label'
+import TaskReminderModel from '@/models/taskReminder'
 
 import type {ILabel} from '@/modelTypes/ILabel'
 import type {ITask} from '@/modelTypes/ITask'
+import type {ITaskReminder} from '@/modelTypes/ITaskReminder'
 import type {IUser} from '@/modelTypes/IUser'
 import type {IAttachment} from '@/modelTypes/IAttachment'
 import type {IProject} from '@/modelTypes/IProject'
 
+import {REMINDER_PERIOD_RELATIVE_TO_TYPES} from '@/types/IReminderPeriodRelativeTo'
+
 import {setModuleLoading} from '@/stores/helper'
 import {useLabelStore} from '@/stores/labels'
 import {useProjectStore} from '@/stores/projects'
@@ -38,6 +42,23 @@ interface MatchedAssignee extends IUser {
 	match: string,
 }
 
+export function buildDefaultRemindersForQuickAdd(
+	defaults: readonly ITaskReminder[] | undefined,
+	dueDate: string | null,
+): ITaskReminder[] {
+	if (!dueDate) {
+		return []
+	}
+	if (!defaults || defaults.length === 0) {
+		return []
+	}
+	return defaults.map(d => new TaskReminderModel({
+		reminder: null,
+		relativePeriod: d.relativePeriod,
+		relativeTo: REMINDER_PERIOD_RELATIVE_TO_TYPES.DUEDATE,
+	}))
+}
+
 // IDEA: maybe use a small fuzzy search here to prevent errors
 function findPropertyByValue(object, key, value, fuzzy = false) {
 	return Object.values(object).find(l => {
@@ -483,6 +504,10 @@ export const useTaskStore = defineStore('task', () => {
 			index,
 		})
 		task.repeatAfter = parsedTask.repeats
+		task.reminders = buildDefaultRemindersForQuickAdd(
+			authStore.settings.frontendSettings.quickAddDefaultReminders,
+			dueDate,
+		)
 
 		if (parsedTask.repeats?.type === REPEAT_TYPES.Months && parsedTask.repeats?.amount === 1) {
 			task.repeatMode = TASK_REPEAT_MODES.REPEAT_MODE_MONTH