fix: resolve TS build errors in sync-engine and SyncSettings

Author: bealqiu

packages/app/package.json

@@ -74,6 +74,7 @@
   "devDependencies": {
     "@tailwindcss/vite": "^4.0.0",
     "@tauri-apps/cli": "^2.10.1",
+    "@types/d3": "^7.4.3",
     "@types/d3-scale": "^4.0.9",
     "@types/d3-shape": "^3.1.8",
     "@types/react": "^19.1.8",

packages/app/src/components/settings/SyncSettings.tsx

@@ -18,7 +18,6 @@ export function SyncSettings() {
     lastSyncAt,
     lastResult,
     error,
-    progress,
     pendingDirection,
     loadConfig,
     testConnection,

packages/core/src/sync/sync-engine.ts

@@ -23,11 +23,11 @@ import {
 /** Get a sync metadata value from the database */
 async function getSyncMeta(key: string): Promise<string | null> {
   const db = await getDB();
-  const rows = await db.select<{ value: string }[]>(
+  const rows = await db.select<{ value: string }>(
     "SELECT value FROM sync_metadata WHERE key = ?",
     [key],
   );
-  return (rows as { value: string }[])[0]?.value ?? null;
+  return rows[0]?.value ?? null;
 }
 
 /** Set a sync metadata value in the database */
@@ -350,7 +350,7 @@ async function syncFiles(
 
   // Get all books from DB
   const books = await db.select<
-    { id: string; file_path: string; file_hash: string; cover_url: string }[]
+    { id: string; file_path: string; file_hash: string; cover_url: string }
   >(
     "SELECT id, file_path, file_hash, cover_url FROM books",
     [],