fix(gantt): sync task updates from detail view back to gantt chart

The Gantt chart maintains its own local task map, separate from the
Pinia task store. When a task is edited in the detail modal, the
update was not propagated to the Gantt's map. Add a lastUpdatedTask
signal to the task store and watch it in useGanttTaskList.

frontend/src/stores/tasks.ts

@@ -114,6 +114,7 @@ export const useTaskStore = defineStore('task', () => {
 	const tasks = ref<{ [id: ITask['id']]: ITask }>({}) // TODO: or is this ITask[]
 	const isLoading = ref(false)
 	const draggedTask = ref<ITask | null>(null)
+	const lastUpdatedTask = ref<ITask | null>(null)
 
 	const hasTasks = computed(() => Object.keys(tasks.value).length > 0)
 
@@ -163,6 +164,7 @@ export const useTaskStore = defineStore('task', () => {
 		try {
 			const updatedTask = await taskService.update(task)
 			kanbanStore.ensureTaskIsInCorrectBucket(updatedTask)
+			lastUpdatedTask.value = updatedTask
 			return updatedTask
 		} finally {
 			cancel()
@@ -541,6 +543,7 @@ export const useTaskStore = defineStore('task', () => {
 		tasks,
 		isLoading,
 		draggedTask,
+		lastUpdatedTask,
 
 		hasTasks,
 

frontend/src/views/project/helpers/useGanttTaskList.ts

@@ -10,6 +10,7 @@ import TaskService from '@/services/task'
 import TaskModel from '@/models/task'
 import {error, success} from '@/message'
 import {useAuthStore} from '@/stores/auth'
+import {useTaskStore} from '@/stores/tasks'
 import type {IProjectView} from '@/modelTypes/IProjectView'
 
 export interface UseGanttTaskListReturn {
@@ -70,6 +71,17 @@ export function useGanttTaskList<F extends Filters>(
 		{immediate: true, deep: true},
 	)
 
+	// Sync task updates from other views (e.g. task detail modal)
+	const taskStore = useTaskStore()
+	watch(
+		() => taskStore.lastUpdatedTask,
+		(updatedTask) => {
+			if (updatedTask && tasks.value.has(updatedTask.id)) {
+				tasks.value.set(updatedTask.id, updatedTask)
+			}
+		},
+	)
+
 	async function addTask(task: Partial<ITask>) {
 		const newTask = await taskService.create(new TaskModel({...task}))
 		tasks.value.set(newTask.id, newTask)