Remove unused terrain commands and functions

src/app/App.tsx

@@ -19,7 +19,6 @@ import { createDeleteBoxBrushCommand } from "../commands/delete-box-brush-comman
 import { createDeleteEntityCommand } from "../commands/delete-entity-command";
 import { createDeleteProjectAssetCommand } from "../commands/delete-project-asset-command";
 import { createDeleteSelectionCommand } from "../commands/delete-selection-command";
-import { createDeleteTerrainCommand } from "../commands/delete-terrain-command";
 import { createDuplicateSelectionCommand } from "../commands/duplicate-selection-command";
 import { createImportAudioAssetCommand } from "../commands/import-audio-asset-command";
 import { createImportBackgroundImageAssetCommand } from "../commands/import-background-image-asset-command";
@@ -58,7 +57,6 @@ import { createSetWorldSettingsCommand } from "../commands/set-world-settings-co
 import { createUpsertEntityCommand } from "../commands/upsert-entity-command";
 import { createUpsertModelInstanceCommand } from "../commands/upsert-model-instance-command";
 import { createUpsertPathCommand } from "../commands/upsert-path-command";
-import { createUpsertTerrainCommand } from "../commands/upsert-terrain-command";
 import { createUpsertInteractionLinkCommand } from "../commands/upsert-interaction-link-command";
 import {
   applySameKindSelectionClick,
@@ -71,13 +69,11 @@ import {
   getSingleSelectedModelInstanceId,
   getSingleSelectedPathOwnerId,
   getSingleSelectedPathPoint,
-  getSingleSelectedTerrainId,
   isBrushFaceSelected,
   isBrushSelected,
   isPathPointSelected,
   isPathSelected,
   isSelectionActiveId,
-  isTerrainSelected,
   resolveSelectionActiveId,
   type EditorSelection
 } from "../core/selection";
@@ -202,13 +198,6 @@ import {
   type ScenePath,
   type ScenePathPoint
 } from "../document/paths";
-import {
-  createTerrain,
-  getTerrainBounds,
-  getTerrainKindLabel,
-  getTerrains,
-  type Terrain
-} from "../document/terrains";
 import {
   areProjectTimeSettingsEqual,
   cloneProjectTimeSettings,
@@ -1091,6 +1080,19 @@ function getSelectedPath(
   return paths.find((path) => path.id === selectedPathId) ?? null;
 }
 
+function getSelectedTerrain(
+  selection: EditorSelection,
+  terrains: Terrain[]
+): Terrain | null {
+  const selectedTerrainId = getSingleSelectedTerrainId(selection);
+
+  if (selectedTerrainId === null) {
+    return null;
+  }
+
+  return terrains.find((terrain) => terrain.id === selectedTerrainId) ?? null;
+}
+
 function getSelectedPathPointState(
   selection: EditorSelection,
   path: ScenePath | null
@@ -1240,6 +1242,17 @@ function getPathLabelById(pathId: string, paths: ScenePath[]): string {
     : getScenePathLabel(paths[pathIndex], pathIndex);
 }
 
+function getTerrainLabel(terrain: Terrain, index: number): string {
+  return terrain.name ?? `Terrain ${index + 1}`;
+}
+
+function getTerrainLabelById(terrainId: string, terrains: Terrain[]): string {
+  const terrainIndex = terrains.findIndex((terrain) => terrain.id === terrainId);
+  return terrainIndex === -1
+    ? getTerrainKindLabel()
+    : getTerrainLabel(terrains[terrainIndex], terrainIndex);
+}
+
 function formatAuthoredObjectStateSummary(state: {
   visible: boolean;
   enabled: boolean;