cleanup: centralise localStorage try/catch in renderer-shared — safeLocalStorageGet/Set/Remove

Every renderer module that persists state was wrapping its localStorage.getItem/setItem/removeItem call in the same try/catch idiom — handling private-browsing quirks and other sandbox contexts where storage isn't writable. Three identical patterns repeated nine times across renderer-streamers (filter / sort / hide-downloaded state), renderer-updates (skipped-update version), and renderer.ts (active-tab persistence).

Introduced three helpers in renderer-shared.ts:
- safeLocalStorageGet(key, fallback = '') — wraps getItem with the try/catch + fallback
- safeLocalStorageSet(key, value) — wraps setItem
- safeLocalStorageRemove(key) — wraps removeItem (needed for clearSkippedUpdateVersion which actually deletes the entry rather than blanking it)

Refactored 9 callsites. Reduces the noise:before:
    try { return localStorage.getItem(KEY) ?? ''; } catch { return ''; }
    try { localStorage.setItem(KEY, value); } catch { /* localStorage may be unavailable */ }
after:
    return safeLocalStorageGet(KEY);
    safeLocalStorageSet(KEY, value);

Left the VOD scroll-positions persistence in renderer-streamers untouched — its surrounding try/catch wraps JSON.parse/stringify logic that doesn't fit the simple helper signature.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/renderer-shared.ts

@@ -19,6 +19,22 @@ function escapeHtml(value: string): string {
         .replace(/'/g, ''');
 }
 
+/* localStorage helpers — every renderer module that persists state was
+   wrapping its get/set calls in the same try/catch idiom to handle
+   environments where localStorage isn't writable (private-browsing
+   quirks, certain sandboxed contexts). Centralising the pattern. */
+function safeLocalStorageGet(key: string, fallback = ''): string {
+    try { return localStorage.getItem(key) ?? fallback; } catch { return fallback; }
+}
+
+function safeLocalStorageSet(key: string, value: string): void {
+    try { localStorage.setItem(key, value); } catch { /* localStorage may be unavailable */ }
+}
+
+function safeLocalStorageRemove(key: string): void {
+    try { localStorage.removeItem(key); } catch { /* localStorage may be unavailable */ }
+}
+
 let config: AppConfig = {};
 let currentStreamer: string | null = null;
 let isConnected = false;

src/renderer-streamers.ts

@@ -53,11 +53,11 @@ const VOD_HIDE_DOWNLOADED_STORAGE_KEY = 'twitch-vod-manager:vod-hide-downloaded'
 let vodHideDownloaded = false;
 
 function loadPersistedHideDownloaded(): boolean {
-    try { return localStorage.getItem(VOD_HIDE_DOWNLOADED_STORAGE_KEY) === '1'; } catch { return false; }
+    return safeLocalStorageGet(VOD_HIDE_DOWNLOADED_STORAGE_KEY) === '1';
 }
 
 function persistHideDownloaded(value: boolean): void {
-    try { localStorage.setItem(VOD_HIDE_DOWNLOADED_STORAGE_KEY, value ? '1' : '0'); } catch { /* ignore */ }
+    safeLocalStorageSet(VOD_HIDE_DOWNLOADED_STORAGE_KEY, value ? '1' : '0');
 }
 
 function onVodHideDownloadedChange(): void {
@@ -78,17 +78,15 @@ const VOD_SORT_STORAGE_KEY = 'twitch-vod-manager:vod-sort';
 let vodSortKey: VodSortKey = 'date_desc';
 
 function loadPersistedVodSort(): VodSortKey {
-    try {
-        const stored = localStorage.getItem(VOD_SORT_STORAGE_KEY);
+    const stored = safeLocalStorageGet(VOD_SORT_STORAGE_KEY);
     if (stored && (VALID_VOD_SORTS as readonly string[]).includes(stored)) {
         return stored as VodSortKey;
     }
-    } catch { /* localStorage may be unavailable */ }
     return 'date_desc';
 }
 
 function persistVodSort(key: VodSortKey): void {
-    try { localStorage.setItem(VOD_SORT_STORAGE_KEY, key); } catch { /* localStorage may be unavailable */ }
+    safeLocalStorageSet(VOD_SORT_STORAGE_KEY, key);
 }
 
 function vodDurationToSeconds(durationStr: string): number {
@@ -162,15 +160,11 @@ function refreshVodSortSelectLabels(): void {
 }
 
 function loadPersistedVodFilter(): string {
-    try {
-        return localStorage.getItem(VOD_FILTER_STORAGE_KEY) ?? '';
-    } catch {
-        return '';
-    }
+    return safeLocalStorageGet(VOD_FILTER_STORAGE_KEY);
 }
 
 function persistVodFilter(query: string): void {
-    try { localStorage.setItem(VOD_FILTER_STORAGE_KEY, query); } catch { /* localStorage may be unavailable */ }
+    safeLocalStorageSet(VOD_FILTER_STORAGE_KEY, query);
 }
 
 function filterVodsByQuery(vods: VOD[], query: string): VOD[] {

src/renderer-updates.ts

@@ -12,15 +12,15 @@ let shouldOpenUpdateModalOnAvailable = false;
 const SKIPPED_UPDATE_VERSION_KEY = 'twitch-vod-manager:skipped-update-version';
 
 function getSkippedUpdateVersion(): string {
-    try { return localStorage.getItem(SKIPPED_UPDATE_VERSION_KEY) || ''; } catch { return ''; }
+    return safeLocalStorageGet(SKIPPED_UPDATE_VERSION_KEY);
 }
 
 function persistSkippedUpdateVersion(version: string): void {
-    try { localStorage.setItem(SKIPPED_UPDATE_VERSION_KEY, version); } catch { /* localStorage may be unavailable */ }
+    safeLocalStorageSet(SKIPPED_UPDATE_VERSION_KEY, version);
 }
 
 function clearSkippedUpdateVersion(): void {
-    try { localStorage.removeItem(SKIPPED_UPDATE_VERSION_KEY); } catch { /* localStorage may be unavailable */ }
+    safeLocalStorageRemove(SKIPPED_UPDATE_VERSION_KEY);
 }
 
 function notifyUpdate(message: string, type: 'info' | 'warn' = 'info'): void {

src/renderer.ts

@@ -836,16 +836,14 @@ function isKnownTab(value: string): value is typeof TAB_IDS[number] {
 }
 
 function loadPersistedActiveTab(): string {
-    try {
-        const stored = localStorage.getItem(ACTIVE_TAB_STORAGE_KEY);
+    const stored = safeLocalStorageGet(ACTIVE_TAB_STORAGE_KEY);
     if (stored && isKnownTab(stored)) return stored;
-    } catch { /* localStorage may be unavailable in privacy modes */ }
     return 'vods';
 }
 
 function persistActiveTab(tab: string): void {
     if (!isKnownTab(tab)) return;
-    try { localStorage.setItem(ACTIVE_TAB_STORAGE_KEY, tab); } catch { }
+    safeLocalStorageSet(ACTIVE_TAB_STORAGE_KEY, tab);
 }
 
 function showTab(tab: string): void {