feat: validate inventory image metadata

Centralize supported MIME type, 10 MiB file-size, and 10,000-pixel dimension limits in the inventory image service boundary. Add domain coverage and update image/status documentation. Verification: npm test passed 64 tests and integration passed 14 tests. No build script is configured.

apps/api/tests/domain/inventory-image.test.js

@@ -0,0 +1,30 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import { validateInventoryImageMetadata } from '../../src/modules/inventory/domain/inventory-image.js';
+
+const validImage = {
+  mimeType: 'image/jpeg',
+  fileSize: 12000,
+  width: 1200,
+  height: 900,
+};
+
+test('accepts supported image metadata within configured limits', () => {
+  assert.equal(validateInventoryImageMetadata(validImage), true);
+});
+
+test('rejects unsupported MIME types, oversized files, and oversized dimensions', () => {
+  assert.throws(
+    () => validateInventoryImageMetadata({ ...validImage, mimeType: 'image/gif' }),
+    (error) => error.code === 'IMAGE_MIME_TYPE_UNSUPPORTED',
+  );
+  assert.throws(
+    () => validateInventoryImageMetadata({ ...validImage, fileSize: 11 * 1024 * 1024 }),
+    (error) => error.code === 'IMAGE_FILE_TOO_LARGE',
+  );
+  assert.throws(
+    () => validateInventoryImageMetadata({ ...validImage, width: 10001 }),
+    (error) => error.code === 'IMAGE_DIMENSIONS_INVALID',
+  );
+});