feat(books): add jump rail navigation to book listings (#318)

Add server-backed jump buckets so large library, collection, and smart-scope listings can jump directly to sorted sections without loading every row up front.

Closes #163

scripts/e2e/suite-registry.mjs

@@ -254,6 +254,25 @@ export const E2E_SUITES = Object.freeze({
       ...SHARED_DB_AND_HELPER_PATHS,
     ],
   },
+  "jump-buckets-invariant": {
+    id: "jump-buckets-invariant",
+    name: "Jump Buckets Invariant",
+    timeout: 45,
+    lane: "full",
+    description: "Asserts jump-bucket indexes match real listing offsets for every eligible sort, direction, and collapse mode",
+    vitestTarget: "test/jump-buckets-invariant.e2e-spec.ts",
+    junitOutput: `${TEST_RESULTS_DIR}/jump-buckets-invariant-e2e-junit.xml`,
+    prepareDedicatedDatabase: true,
+    useDedicatedDatabase: true,
+    changedPaths: [
+      "server/src/modules/book/**",
+      "server/src/modules/library/**",
+      "server/src/db/book-author-sort-key.ts",
+      "server/test/jump-buckets-invariant.e2e-spec.ts",
+      ...SHARED_TYPES_PATHS,
+      ...SHARED_DB_AND_HELPER_PATHS,
+    ],
+  },
   "app-settings-oidc-contract": {
     id: "app-settings-oidc-contract",
     name: "App Settings OIDC Contract",