fix(scanner): keep audiobook tracks in file name order

The player follows each track's stored sort order, which overlapping
folder scans, Add File, and imports joining a book could leave out of
step with the file names the Files tab shows. Realign a book's tracks
after each of those writes, under the book row lock.

Closes #1681

scripts/e2e/suite-registry.mjs

@@ -101,6 +101,29 @@ export const E2E_SUITES = Object.freeze({
       ...SHARED_DB_AND_HELPER_PATHS,
     ],
   },
+  "audiobook-track-order": {
+    id: "audiobook-track-order",
+    name: "Audiobook Track Order",
+    timeout: 45,
+    lane: "full",
+    description: "Audiobook playback order matches file names after overlapping scans and added tracks",
+    vitestTarget: "test/audiobook-track-order.e2e-spec.ts",
+    junitOutput: `${TEST_RESULTS_DIR}/audiobook-track-order-e2e-junit.xml`,
+    prepareDedicatedDatabase: true,
+    useDedicatedDatabase: true,
+    changedPaths: [
+      "server/src/common/utils/audio-track-order.utils.ts",
+      "server/src/common/utils/book-media.utils.ts",
+      "server/src/db/audio-track-order.ts",
+      "server/src/modules/audiobook/**",
+      "server/src/modules/scanner/**",
+      "server/src/modules/upload/**",
+      "server/test/audiobook-track-order.e2e-spec.ts",
+      "server/test/e2e/scanner/**",
+      ".github/workflows/e2e-runner.yml",
+      ...SHARED_DB_AND_HELPER_PATHS,
+    ],
+  },
   "auth-session-security": {
     id: "auth-session-security",
     name: "Auth Session Security",