feat: item-attachments CRUD (#22)

* change /content/ -> /homebox/

* add cache to code generators

* update env variables to set data storage

* update env variables

* set env variables in prod container

* implement attachment post route (WIP)

* get attachment endpoint

* attachment download

* implement string utilities lib

* implement generic drop zone

* use explicit truncate

* remove clean dir

* drop strings composable for lib

* update item types and add attachments

* add attachment API

* implement service context

* consolidate API code

* implement editing attachments

* implement upload limit configuration

* improve error handling

* add docs for max upload size

* fix test cases

frontend/composables/use-strings.ts

@@ -1,7 +0,0 @@
-export function truncate(str: string, length: number) {
-  return str.length > length ? str.substring(0, length) + "..." : str;
-}
-
-export function capitalize(str: string) {
-  return str.charAt(0).toUpperCase() + str.slice(1);
-}