test: reorganize flat test files into purpose-based subdirectories (phase 6)

Group 245 flat integration tests and 25 loose unit tests into
discoverable subdirectories per spec section 6:

  integration/tools/{image,video,audio,document,data}/  (156 files)
  integration/platform/                                  (64 files)
  integration/generated/                                 (14 files)
  integration/security/                                  (10 files)

  unit/security/     (8 files, new subdir)
  unit/api/          (7 files moved in)
  unit/web/          (3 files moved in)
  unit/shared/       (6 files moved in)
  unit/image-engine/ (1 file moved in)

All moves via git mv (history preserved). Relative imports repaired
for both depth levels (platform/generated/security = +1, tools/ = +2):
static from-imports, dynamic import() calls, vi.mock() paths,
import.meta.dirname joins, and __dirname joins.

Vitest discovery unchanged (no test.include in config, recursive glob
matches subdirs, shard-by-hash unaffected). test-server.ts and
tool-route-drift.test.ts stay at integration root. fixtures/ untouched.

Parity gate: 13189 passing test names before = 13189 after (0 dropped).

tests/integration/tools/image/sprite-sheet.test.ts

@@ -0,0 +1,156 @@
+/**
+ * Integration tests for the sprite-sheet tool (/api/v1/tools/sprite-sheet).
+ *
+ * Covers grid layout, dimension math, frames payload, and minimum input guard.
+ */
+
+import sharp from "sharp";
+import { afterAll, beforeAll, describe, expect, it } from "vitest";
+import { fixtures, readFixture } from "../../../fixtures/index.js";
+import {
+  buildTestApp,
+  createMultipartPayload,
+  loginAsAdmin,
+  type TestApp,
+} from "../../test-server.js";
+
+const PNG = readFixture(fixtures.image.base.png200);
+const JPG = readFixture(fixtures.image.base.jpg100);
+
+let testApp: TestApp;
+let app: TestApp["app"];
+let adminToken: string;
+
+beforeAll(async () => {
+  testApp = await buildTestApp();
+  app = testApp.app;
+  adminToken = await loginAsAdmin(app);
+}, 30_000);
+
+afterAll(async () => {
+  await testApp.cleanup();
+}, 10_000);
+
+describe("Sprite Sheet", () => {
+  it("creates a sprite sheet from 4 images with 2 columns", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "a.png", contentType: "image/png", content: PNG },
+      { name: "file", filename: "b.png", contentType: "image/png", content: PNG },
+      { name: "file", filename: "c.jpg", contentType: "image/jpeg", content: JPG },
+      { name: "file", filename: "d.jpg", contentType: "image/jpeg", content: JPG },
+      { name: "settings", content: JSON.stringify({ columns: 2 }) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/sprite-sheet",
+      headers: {
+        authorization: `Bearer ${adminToken}`,
+        "content-type": contentType,
+      },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const result = JSON.parse(res.body);
+    expect(result.downloadUrl).toBeDefined();
+    expect(result.frames).toHaveLength(4);
+
+    // Download and verify dimensions: 2 cols x 2 rows of 200x150 cells
+    const dlRes = await app.inject({
+      method: "GET",
+      url: result.downloadUrl,
+      headers: { authorization: `Bearer ${adminToken}` },
+    });
+    const meta = await sharp(dlRes.rawPayload).metadata();
+    // First image is 200x150, so cells are 200x150
+    // 2 cols, 2 rows, no padding
+    expect(meta.width).toBe(200 * 2);
+    expect(meta.height).toBe(150 * 2);
+  });
+
+  it("returns full coordinate map in resultPayload", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "a.png", contentType: "image/png", content: PNG },
+      { name: "file", filename: "b.jpg", contentType: "image/jpeg", content: JPG },
+      { name: "settings", content: JSON.stringify({ columns: 2 }) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/sprite-sheet",
+      headers: {
+        authorization: `Bearer ${adminToken}`,
+        "content-type": contentType,
+      },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const result = JSON.parse(res.body);
+
+    // frames array
+    expect(Array.isArray(result.frames)).toBe(true);
+    expect(result.frames).toHaveLength(2);
+    expect(result.frames[0]).toMatchObject({ index: 0, left: 0, top: 0 });
+
+    // grid metadata
+    expect(result.cols).toBe(2);
+    expect(result.rows).toBe(1);
+    expect(result.cellWidth).toBe(200);
+    expect(result.cellHeight).toBe(150);
+    expect(result.canvasWidth).toBe(400);
+    expect(result.canvasHeight).toBe(150);
+  });
+
+  it("outputs webp when format is webp", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "a.png", contentType: "image/png", content: PNG },
+      { name: "file", filename: "b.png", contentType: "image/png", content: PNG },
+      { name: "settings", content: JSON.stringify({ columns: 2, format: "webp" }) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/sprite-sheet",
+      headers: {
+        authorization: `Bearer ${adminToken}`,
+        "content-type": contentType,
+      },
+      body,
+    });
+
+    expect(res.statusCode).toBe(200);
+    const result = JSON.parse(res.body);
+    expect(result.downloadUrl).toBeDefined();
+
+    const dlRes = await app.inject({
+      method: "GET",
+      url: result.downloadUrl,
+      headers: { authorization: `Bearer ${adminToken}` },
+    });
+    const meta = await sharp(dlRes.rawPayload).metadata();
+    expect(meta.format).toBe("webp");
+  });
+
+  it("rejects single input", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "a.png", contentType: "image/png", content: PNG },
+      { name: "settings", content: JSON.stringify({}) },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/sprite-sheet",
+      headers: {
+        authorization: `Bearer ${adminToken}`,
+        "content-type": contentType,
+      },
+      body,
+    });
+
+    // The factory wraps InputValidationError as 422
+    expect(res.statusCode).toBeGreaterThanOrEqual(400);
+    expect(res.statusCode).toBeLessThan(500);
+  });
+});