feat!: port DS4 actor sheets to ApplicationV2

Convert DS4ActorSheet, DS4CharacterActorSheet, and DS4CreatureActorSheet
from ApplicationV1 to ApplicationV2 architecture. Update all templates
to use data-action attributes. Implement manual tab system and preserve
all existing functionality including item management, effects, and
rolling system.

BREAKING CHANGE: Requires FoundryVTT ApplicationV2 system

templates/sheets/actor/components/check.hbs

@@ -12,7 +12,7 @@ SPDX-License-Identifier: MIT
 !-- @param check-label: The label for the check
 --}}
 
-<button class="ds4-check rollable-check" data-check="{{check-key}}"
+<button class="ds4-check" data-action="rollCheck" data-check="{{check-key}}"
     title="{{localize 'DS4.CheckTooltip' check=check-label}}">
     <span>{{check-label}}</span>
     <span>{{check-target-number}}</span>