Update material names and add tests for box face UVs and scene document migration

tests/e2e/face-material-authoring.e2e.ts

@@ -27,14 +27,14 @@ test("user can assign a face material through the UI and keep it through an auto
   await page.getByTestId("face-button-posZ").click();
   await page.getByTestId("material-button-starter-amber-grid").click();
 
-  await expect(page.getByTestId("selected-face-material-name")).toContainText("Amber Grid");
+  await expect(page.getByTestId("selected-face-material-name")).toContainText("Stacked Beige Terracotta Tile");
 
   await page.waitForTimeout(400);
   await page.reload();
 
   await page.getByRole("button", { name: /Whitebox Box 1/ }).click();
   await page.getByTestId("face-button-posZ").click();
-  await expect(page.getByTestId("selected-face-material-name")).toContainText("Amber Grid");
+  await expect(page.getByTestId("selected-face-material-name")).toContainText("Stacked Beige Terracotta Tile");
 
   expect(pageErrors).toEqual([]);
   expect(consoleErrors).toEqual([]);

tests/e2e/first-room-workflow.e2e.ts

@@ -50,7 +50,7 @@ test("first-room workflow covers create, texture, autosave recovery, and run", a
 
   await page.getByRole("button", { name: /Whitebox Box 1/ }).click();
   await page.getByTestId("face-button-posZ").click();
-  await expect(page.getByTestId("selected-face-material-name")).toContainText("Amber Grid");
+  await expect(page.getByTestId("selected-face-material-name")).toContainText("Stacked Beige Terracotta Tile");
 
   await page.getByTestId("enter-run-mode").click();
 

tests/geometry/box-face-uvs.test.ts

@@ -2,7 +2,12 @@ import { BoxGeometry } from "three";
 import { describe, expect, it } from "vitest";
 
 import { createBoxBrush } from "../../src/document/brushes";
-import { applyBoxBrushFaceUvsToGeometry, createFitToFaceBoxBrushFaceUvState, transformProjectedFaceUv } from "../../src/geometry/box-face-uvs";
+import {
+  applyBoxBrushFaceUvsToGeometry,
+  createFitToFaceBoxBrushFaceUvState,
+  createFitToMaterialTileBoxBrushFaceUvState,
+  transformProjectedFaceUv
+} from "../../src/geometry/box-face-uvs";
 
 describe("box face UV projection", () => {
   it("fit-to-face produces finite UVs normalized across the target face", () => {
@@ -73,4 +78,24 @@ describe("box face UV projection", () => {
     expect(transformedUv.x).toBeCloseTo(2.5);
     expect(transformedUv.y).toBeCloseTo(-0.25);
   });
+
+  it("fits one authored material tile across the face bounds", () => {
+    const brush = createBoxBrush({
+      size: {
+        x: 5,
+        y: 2,
+        z: 4
+      }
+    });
+
+    const uvState = createFitToMaterialTileBoxBrushFaceUvState(brush, "posZ", {
+      x: 2.5,
+      y: 2.5
+    });
+
+    expect(uvState.scale).toEqual({
+      x: 0.5,
+      y: 1.25
+    });
+  });
 });

tests/serialization/scene-document-json.test.ts

@@ -28,6 +28,7 @@ import {
   PLAYER_START_NAVIGATION_MODE_SCENE_DOCUMENT_VERSION,
   SCENE_EDITOR_PREFERENCES_SCENE_DOCUMENT_VERSION,
   SCENE_TRANSITION_ENTITIES_SCENE_DOCUMENT_VERSION,
+  SCENE_TRANSITION_SEQUENCE_EFFECTS_SCENE_DOCUMENT_VERSION,
   SCENE_DOCUMENT_VERSION,
   SPATIAL_AUDIO_SCENE_DOCUMENT_VERSION,
   STATIC_SIMPLE_MODEL_COLLIDERS_SCENE_DOCUMENT_VERSION,
@@ -1991,6 +1992,56 @@ describe("scene document JSON", () => {
     });
   });
 
+  it("migrates legacy starter material entries to the asset-backed PBR registry", () => {
+    const legacyDocument = createEmptySceneDocument({
+      name: "Legacy Material Registry Scene"
+    });
+    const legacyBrush = createBoxBrush({
+      id: "brush-legacy-materials",
+      size: {
+        x: 4,
+        y: 2,
+        z: 4
+      }
+    });
+
+    legacyBrush.faces.posZ.materialId = "starter-amber-grid";
+    legacyDocument.brushes[legacyBrush.id] = legacyBrush;
+
+    const migratedDocument = migrateSceneDocument({
+      ...legacyDocument,
+      version: SCENE_TRANSITION_SEQUENCE_EFFECTS_SCENE_DOCUMENT_VERSION,
+      materials: {
+        ...legacyDocument.materials,
+        "starter-amber-grid": {
+          id: "starter-amber-grid",
+          name: "Amber Grid",
+          pattern: "grid",
+          baseColorHex: "#d97706",
+          accentColorHex: "#fbbf24",
+          tags: ["warm", "grid"]
+        }
+      }
+    });
+
+    expect(migratedDocument.version).toBe(SCENE_DOCUMENT_VERSION);
+    expect(
+      migratedDocument.brushes["brush-legacy-materials"].faces.posZ.materialId
+    ).toBe("starter-amber-grid");
+    expect(migratedDocument.materials["starter-amber-grid"]).toEqual(
+      expect.objectContaining({
+        id: "starter-amber-grid",
+        name: "Stacked Beige Terracotta Tile",
+        assetFolder: "stacked_beige_terracotta_tile_250x250",
+        previewImageName: "preview.webp",
+        sizeCm: {
+          width: 250,
+          height: 250
+        }
+      })
+    );
+  });
+
   it("migrates slice 1.2 face materials to the PlayerStart-capable schema", () => {
     const migratedDocument = migrateSceneDocument({
       version: 3,