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>

module/applications/sheets/settlement-sheet.mjs

@@ -0,0 +1,132 @@
+import OathHammerActorSheet from "./base-actor-sheet.mjs"
+
+const ALLOWED_ITEM_TYPES = new Set(["building", "equipment", "weapon", "armor"])
+
+export default class OathHammerSettlementSheet extends OathHammerActorSheet {
+  /** @override */
+  static DEFAULT_OPTIONS = {
+    classes: ["settlement"],
+    position: {
+      width: 840,
+      height: "auto",
+    },
+    window: {
+      contentClasses: ["settlement-content"],
+    },
+    actions: {
+      adjustCurrency: OathHammerSettlementSheet.#onAdjustCurrency,
+      adjustQty:      OathHammerSettlementSheet.#onAdjustQty,
+      toggleConstructed: OathHammerSettlementSheet.#onToggleConstructed,
+    },
+  }
+
+  /** @override */
+  static PARTS = {
+    main: {
+      template: "systems/fvtt-oath-hammer/templates/actor/settlement-sheet.hbs",
+    },
+    tabs: {
+      template: "templates/generic/tab-navigation.hbs",
+    },
+    overview: {
+      template: "systems/fvtt-oath-hammer/templates/actor/settlement-overview.hbs",
+    },
+    buildings: {
+      template: "systems/fvtt-oath-hammer/templates/actor/settlement-buildings.hbs",
+    },
+    inventory: {
+      template: "systems/fvtt-oath-hammer/templates/actor/settlement-inventory.hbs",
+    },
+  }
+
+  /** @override */
+  tabGroups = {
+    sheet: "overview",
+  }
+
+  #getTabs() {
+    const tabs = {
+      overview:  { id: "overview",  group: "sheet", icon: "fa-solid fa-city",        label: "OATHHAMMER.Tab.Overview" },
+      buildings: { id: "buildings", group: "sheet", icon: "fa-solid fa-building",     label: "OATHHAMMER.Tab.Buildings" },
+      inventory: { id: "inventory", group: "sheet", icon: "fa-solid fa-boxes-stacked", label: "OATHHAMMER.Tab.Inventory" },
+    }
+    for (const v of Object.values(tabs)) {
+      v.active   = this.tabGroups[v.group] === v.id
+      v.cssClass = v.active ? "active" : ""
+    }
+    return tabs
+  }
+
+  /** @override */
+  async _prepareContext() {
+    const context = await super._prepareContext()
+    context.tabs = this.#getTabs()
+    context.archetypeChoices = Object.fromEntries(
+      Object.entries(SYSTEM.SETTLEMENT_ARCHETYPES).map(([k, v]) => [k, game.i18n.localize(v)])
+    )
+    return context
+  }
+
+  /** @override */
+  async _preparePartContext(partId, context) {
+    const doc = this.document
+    switch (partId) {
+      case "main":
+        break
+      case "overview":
+        context.tab = context.tabs.overview
+        context.enrichedDescription = await foundry.applications.ux.TextEditor.implementation.enrichHTML(
+          doc.system.description, { async: true }
+        )
+        break
+      case "buildings":
+        context.tab = context.tabs.buildings
+        context.buildings = doc.itemTypes.building
+        break
+      case "inventory": {
+        context.tab = context.tabs.inventory
+        context.weapons    = doc.itemTypes.weapon
+        context.armors     = doc.itemTypes.armor
+        context.equipments = doc.itemTypes.equipment
+        break
+      }
+    }
+    return context
+  }
+
+  /** @override */
+  async _onDrop(event) {
+    if (!this.isEditable || !this.isEditMode) return
+    const data = foundry.applications.ux.TextEditor.implementation.getDragEventData(event)
+    if (data.type !== "Item") return
+    const item = await fromUuid(data.uuid)
+    if (!item || !ALLOWED_ITEM_TYPES.has(item.type)) return
+    return this._onDropItem(item)
+  }
+
+  static async #onAdjustCurrency(event, target) {
+    const field = target.dataset.field
+    const delta = parseInt(target.dataset.delta, 10)
+    if (!field || isNaN(delta)) return
+    const current = foundry.utils.getProperty(this.document, field) ?? 0
+    await this.document.update({ [field]: Math.max(0, current + delta) })
+  }
+
+  static async #onAdjustQty(event, target) {
+    const itemId = target.dataset.itemId
+    const delta  = parseInt(target.dataset.delta, 10)
+    if (!itemId || isNaN(delta)) return
+    const item = this.document.items.get(itemId)
+    if (!item) return
+    const current = item.system.quantity ?? 0
+    await item.update({ "system.quantity": Math.max(0, current + delta) })
+  }
+
+  static async #onToggleConstructed(event, target) {
+    const itemId = target.dataset.itemId
+    if (!itemId) return
+    const item = this.document.items.get(itemId)
+    if (!item) return
+    await item.update({ "system.constructed": !item.system.constructed })
+  }
+}