feat: add Settlement actor type with Overview/Buildings/Inventory tabs

- New TypeDataModel: archetype, territory, renown, currency (gp/sp/cp),
  garrison, underSiege, isCapital, founded, taxNotes, description, notes
- 3-tab ApplicationV2 sheet with drag & drop for building/weapon/armor/equipment
- Currency steppers (+/−), building constructed toggle, qty controls
- LESS-based CSS (settlement-sheet.less) + base.less updated for shared styles
- Full i18n keys in lang/en.json (8 settlement archetypes)
- system.json: registered settlement actor type

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

templates/actor/settlement-sheet.hbs

@@ -0,0 +1,47 @@
+<div class="settlement-main settlement-main-{{ifThen isPlayMode 'play' 'edit'}}">
+  <header class="settlement-header flexrow">
+    <img class="actor-img" src="{{actor.img}}" data-edit="img" data-action="editImage" data-tooltip="{{actor.name}}" />
+    <div class="settlement-header-info">
+      <div class="settlement-name-row flexrow">
+        {{formInput fields.name value=source.name rootId=partId disabled=isPlayMode}}
+        {{#unless isPlayMode}}
+        {{formInput systemFields.archetype value=system.archetype name="system.archetype" localize=true}}
+        {{else}}
+        <span class="settlement-archetype-badge">{{localize (lookup archetypeChoices system.archetype)}}</span>
+        {{/unless}}
+        <a class="control" data-action="toggleSheet" data-tooltip="OATHHAMMER.ToggleSheet" data-tooltip-direction="UP">
+          <i class="fa-solid fa-{{ifThen isPlayMode 'lock' 'pen'}}"></i>
+        </a>
+      </div>
+      <div class="settlement-stats flexrow">
+        <div class="stat-item">
+          <label>{{localize "OATHHAMMER.Label.Renown"}}</label>
+          {{formInput systemFields.renown value=system.renown name="system.renown" disabled=isPlayMode}}
+        </div>
+        <div class="stat-item">
+          <label>{{localize "OATHHAMMER.Label.Territory"}}</label>
+          {{formInput systemFields.territory value=system.territory name="system.territory" disabled=isPlayMode}}
+        </div>
+        <div class="stat-item">
+          <label>{{localize "OATHHAMMER.Label.Population"}}</label>
+          {{formInput systemFields.population value=system.population name="system.population" disabled=isPlayMode}}
+        </div>
+        <div class="stat-item stat-item--flags">
+          {{#unless isPlayMode}}
+          <label>
+            {{formInput systemFields.isCapital value=system.isCapital name="system.isCapital"}}
+            {{localize "OATHHAMMER.Label.IsCapital"}}
+          </label>
+          <label>
+            {{formInput systemFields.underSiege value=system.underSiege name="system.underSiege"}}
+            {{localize "OATHHAMMER.Label.UnderSiege"}}
+          </label>
+          {{else}}
+          {{#if system.isCapital}}<span class="settlement-badge settlement-badge--capital">★ {{localize "OATHHAMMER.Label.Capital"}}</span>{{/if}}
+          {{#if system.underSiege}}<span class="settlement-badge settlement-badge--siege">⚔ {{localize "OATHHAMMER.Label.UnderSiege"}}</span>{{/if}}
+          {{/unless}}
+        </div>
+      </div>
+    </div>
+  </header>
+</div>