feat(time-tracking) : add TimeEntry DTO, service, timer store, and i18n keys

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

frontend/services/dto/time-entry.ts

@@ -0,0 +1,28 @@
+import type { UserData } from './user-data'
+import type { Project } from './project'
+import type { Task } from './task'
+import type { TaskType } from './task-type'
+
+export type TimeEntry = {
+    id: number
+    '@id'?: string
+    title: string | null
+    description: string | null
+    startedAt: string
+    stoppedAt: string | null
+    user: UserData
+    project: Project | null
+    task: Task | null
+    types: TaskType[]
+}
+
+export type TimeEntryWrite = {
+    title?: string | null
+    description?: string | null
+    startedAt: string
+    stoppedAt?: string | null
+    user: string
+    project?: string | null
+    task?: string | null
+    types?: string[]
+}