feat: complete offline write support with mutation queue + runtime SW cache config

- Add offline CRUD to todoRepo, budgetRepo, reservationRepo, accommodationRepo,
  dayRepo, tripRepo, fileRepo with optimistic Dexie writes and mutation queue
- Wire all store slices (todo, budget, reservations, files, dayNotes, assignments,
  tripStore) through repos for offline-aware writes
- Cover archive/unarchive, file toggleStar/update/delete, assignment create/delete,
  day title/notes update offline paths
- Migrate service worker from generateSW to injectManifest (custom sw.ts) with
  runtime-configurable api-data (7d/500) and map-tiles (30d/1000) cache policies
- Add Settings → Offline cache configuration UI with save/reset and live SW postMessage
- Extend mutationQueue flush to cover all writable Dexie tables

client/src/repo/todoRepo.ts

@@ -1,5 +1,6 @@
 import { todoApi } from '../api/client'
 import { offlineDb, upsertTodoItems } from '../db/offlineDb'
+import { mutationQueue, generateUUID } from '../sync/mutationQueue'
 import type { TodoItem } from '../types'
 
 export const todoRepo = {
@@ -15,4 +16,75 @@ export const todoRepo = {
     upsertTodoItems(result.items)
     return result
   },
+
+  async create(tripId: number | string, data: Record<string, unknown>): Promise<{ item: TodoItem }> {
+    if (!navigator.onLine) {
+      const tempId = -(Date.now())
+      const tempItem: TodoItem = {
+        ...(data as Partial<TodoItem>),
+        id: tempId,
+        trip_id: Number(tripId),
+        name: (data.name as string) ?? 'New todo',
+        checked: 0,
+        sort_order: 0,
+        due_date: null,
+        description: null,
+        assigned_user_id: null,
+        priority: 0,
+      } as TodoItem
+      await offlineDb.todoItems.put(tempItem)
+      await mutationQueue.enqueue({
+        id: generateUUID(),
+        tripId: Number(tripId),
+        method: 'POST',
+        url: `/trips/${tripId}/todo`,
+        body: data,
+        resource: 'todoItems',
+        tempId,
+      })
+      return { item: tempItem }
+    }
+    const result = await todoApi.create(tripId, data)
+    offlineDb.todoItems.put(result.item)
+    return result
+  },
+
+  async update(tripId: number | string, id: number, data: Record<string, unknown>): Promise<{ item: TodoItem }> {
+    if (!navigator.onLine) {
+      const existing = await offlineDb.todoItems.get(id)
+      const optimistic: TodoItem = { ...(existing ?? {} as TodoItem), ...(data as Partial<TodoItem>), id }
+      await offlineDb.todoItems.put(optimistic)
+      await mutationQueue.enqueue({
+        id: generateUUID(),
+        tripId: Number(tripId),
+        method: 'PUT',
+        url: `/trips/${tripId}/todo/${id}`,
+        body: data,
+        resource: 'todoItems',
+      })
+      return { item: optimistic }
+    }
+    const result = await todoApi.update(tripId, id, data)
+    offlineDb.todoItems.put(result.item)
+    return result
+  },
+
+  async delete(tripId: number | string, id: number): Promise<unknown> {
+    if (!navigator.onLine) {
+      await offlineDb.todoItems.delete(id)
+      await mutationQueue.enqueue({
+        id: generateUUID(),
+        tripId: Number(tripId),
+        method: 'DELETE',
+        url: `/trips/${tripId}/todo/${id}`,
+        body: undefined,
+        resource: 'todoItems',
+        entityId: id,
+      })
+      return { success: true }
+    }
+    const result = await todoApi.delete(tripId, id)
+    offlineDb.todoItems.delete(id)
+    return result
+  },
 }