feat(roadtrip): add daily scheduling and configurable day endings

client/src/db/cacheAssignment.ts

@@ -0,0 +1,8 @@
+import { offlineDb } from './offlineDb'
+import type { Assignment } from '../types'
+
+export async function cacheAssignment(assignment: Assignment): Promise<void> {
+  await offlineDb.days.where('id').equals(assignment.day_id).modify(day => {
+    day.assignments = (day.assignments ?? []).map(a => a.id === assignment.id ? { ...a, ...assignment } : a)
+  })
+}