Refactor scripts grid and filter handling for robustness

Improves type safety and normalization in filter, repository, and script status handling across multiple components. Refactors ScriptsGrid for better readability, deduplication, and error messaging, and updates UI markup for consistency. Also adds explicit types for auto-sync settings and ensures string conversion for credential fields.

src/app/_components/DownloadedScriptsTab.tsx

@@ -67,7 +67,9 @@ export function DownloadedScriptsTab({
         if (saveFilterEnabled) {
           const filtersResponse = await fetch("/api/settings/filters");
           if (filtersResponse.ok) {
-            const filtersData = await filtersResponse.json();
+            const filtersData = (await filtersResponse.json()) as {
+              filters?: Partial<FilterState>;
+            };
             if (filtersData.filters) {
               setFilters(mergeFiltersWithDefaults(filtersData.filters));
             }