feat: implement drag-and-drop reordering for checklist items (#275)

* feat: implement drag-and-drop reordering for checklist items

* WIP: Changes before syncing with main

* feat: update drag icon and positioning

* refactor: consolidate checklist item updates into single endpoint

- Remove standalone reorderItem route (now part of updateItem)
- Add optional index parameter to updateItem for reordering
- Change updateItem from PUT to PATCH method
- Add deletedAt IS NULL filter to reorderItem SQL queries
- Follows existing pattern from card.update route

* feat: add optimistic updates

* chore: translations

---------

Co-authored-by: Henry <henry_ball@hotmail.co.uk>

apps/web/i18n.lock

@@ -502,6 +502,7 @@ checksums:
     Trusted%20by%20fast-moving%20teams%3C0%2F%3Earound%20the%20world/singular: b065575df380536df9541a91ca9b37bf
     Unable%20to%20add%20checklist%20item/singular: 4c4c3eaaf10b348b39ae97eb5dc455df
     Unable%20to%20add%20comment/singular: 49bb435880817434698f31a6069564d6
+    Unable%20to%20add%20label/singular: b09fda6420ea1dc10dbea0b1dc373f29
     Unable%20to%20create%20card/singular: 90112ea12ec6fa42097a6e022ae048a4
     Unable%20to%20create%20checklist/singular: 94eed122e42e0951cd08b9ec62f5eeb6
     Unable%20to%20create%20list/singular: 7fbbf8314f8d08a4123c7daef09fed05
@@ -513,6 +514,7 @@ checksums:
     Unable%20to%20delete%20checklist%20item/singular: a74144593b625e4d8d7ecf734462c60d
     Unable%20to%20delete%20comment/singular: 550198b2c87f06726a843c79c1026ed9
     Unable%20to%20remove%20member/singular: 39025a0c53818438829603d213baef06
+    Unable%20to%20reorder%20checklist%20item/singular: dcc238c72b85daf74ebd46adcd914473
     Unable%20to%20send%20feedback/singular: 656c93265d7e2bef1245b17d85f85ae5
     Unable%20to%20update%20board%20URL/singular: 080746884059142358b58d9a44ff7d93
     Unable%20to%20update%20board%20visibility/singular: a76a21d561b8943e9276e027a1e3f70d