i18n: localize 2 hardcoded English alt texts on dynamic <img> elements

Two <img> elements rendered by renderer code had hardcoded English alt text that never localized:

- renderer.ts cutter preview frame: alt="Preview"
- renderer-profile.ts live-thumb: alt="Live preview"

Added two new locale keys (DE+EN):
- cutter.previewAlt — "Vorschau" / "Preview"
- profile.liveThumbAlt — "Live-Vorschau" / "Live preview"

renderer.ts updates: the three preview.innerHTML assignments switched to applyHtml + escapeHtml since the file's previous innerHTML pattern was running afoul of the security lint hook now that escapeHtml is in the template. Same shape as the other consolidated renderers (stats, archive, profile).

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

src/renderer-locale-de.ts

@@ -332,6 +332,7 @@ const UI_TEXT_DE = {
         openTwitch: 'Auf Twitch oeffnen',
         openTwitchTooltip: 'Diesen Kanal auf twitch.tv oeffnen',
         liveCardTooltip: 'Klick um sofort eine Live-Aufnahme zu starten',
+        liveThumbAlt: 'Live-Vorschau',
         recordNow: 'Jetzt aufnehmen',
         refresh: 'Aktualisieren',
         agoMinutes: 'vor {n} Min',
@@ -443,6 +444,7 @@ const UI_TEXT_DE = {
         videoInfoFailed: 'Konnte Video-Informationen nicht lesen. FFprobe installiert?',
         previewLoading: 'Lade Vorschau...',
         previewUnavailable: 'Vorschau nicht verfugbar',
+        previewAlt: 'Vorschau',
         cutting: 'Schneidet...',
         cut: 'Schneiden',
         cutSuccess: 'Video erfolgreich geschnitten!',

src/renderer-locale-en.ts

@@ -332,6 +332,7 @@ const UI_TEXT_EN = {
         openTwitch: 'Open on Twitch',
         openTwitchTooltip: 'Open this channel on twitch.tv',
         liveCardTooltip: 'Click to start a live recording right now',
+        liveThumbAlt: 'Live preview',
         recordNow: 'Record now',
         refresh: 'Refresh',
         agoMinutes: '{n} min ago',
@@ -443,6 +444,7 @@ const UI_TEXT_EN = {
         videoInfoFailed: 'Could not read video info. Is FFprobe installed?',
         previewLoading: 'Loading preview...',
         previewUnavailable: 'Preview unavailable',
+        previewAlt: 'Preview',
         cutting: 'Cutting...',
         cut: 'Cut',
         cutSuccess: 'Video cut successfully!',

src/renderer-profile.ts

@@ -106,7 +106,7 @@ function renderStreamerProfileCard(p: StreamerProfile): void {
         ? `
             <div class="streamer-profile-live-card" role="button" tabindex="0" aria-label="${escapeHtml(UI_TEXT.profile.liveCardTooltip)}" onclick="triggerLiveRecordingFromProfile('${safeLogin}')" onkeydown="if((event.key==='Enter'||event.key===' ')&&event.target===event.currentTarget){event.preventDefault();triggerLiveRecordingFromProfile('${safeLogin}');}" title="${escapeHtml(UI_TEXT.profile.liveCardTooltip)}">
                 ${p.currentStreamPreviewUrl
-                    ? `<img class="streamer-profile-live-thumb" src="${escapeHtml(p.currentStreamPreviewUrl)}" alt="Live preview" onerror="onProfileLivePreviewError(this)">`
+                    ? `<img class="streamer-profile-live-thumb" src="${escapeHtml(p.currentStreamPreviewUrl)}" alt="${escapeHtml(UI_TEXT.profile.liveThumbAlt)}" onerror="onProfileLivePreviewError(this)">`
                     : `<div class="streamer-profile-live-thumb-fallback"></div>`}
                 <div class="streamer-profile-live-body">
                     <div class="streamer-profile-live-badge-row">

src/renderer.ts

@@ -1557,15 +1557,15 @@ async function updatePreview(time: number): Promise<void> {
     }
 
     const preview = byId('cutterPreview');
-    preview.innerHTML = `<div class="placeholder"><p>${UI_TEXT.cutter.previewLoading}</p></div>`;
+    applyHtml(preview, `<div class="placeholder"><p>${escapeHtml(UI_TEXT.cutter.previewLoading)}</p></div>`);
 
     const frame = await window.api.extractFrame(cutterFile, time);
     if (frame) {
-        preview.innerHTML = `<img src="${frame}" alt="Preview">`;
+        applyHtml(preview, `<img src="${escapeHtml(frame)}" alt="${escapeHtml(UI_TEXT.cutter.previewAlt)}">`);
         return;
     }
 
-    preview.innerHTML = `<div class="placeholder"><p>${UI_TEXT.cutter.previewUnavailable}</p></div>`;
+    applyHtml(preview, `<div class="placeholder"><p>${escapeHtml(UI_TEXT.cutter.previewUnavailable)}</p></div>`);
 }
 
 async function startCutting(): Promise<void> {