feat(viewer): loop toggle in video player settings (#3508)

Adds a Loop switch to the video player's settings panel. The choice is
persisted via the player's local storage so it survives across files
and sessions.

Authored By: TDvorak <info@tdvorak.dev>

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

frontend/public/locales/en-US/application.json

@@ -230,6 +230,7 @@
     "color": "Color",
     "fontSize": "Font size",
     "disableSubtitle": "Disable subtitle",
+    "loop": "Loop",
     "noSubtitle": "No ASS/SRT/VTT subtitle files found under current folder.",
     "subtitleStyles": "Subtitle styles",
     "subtitles": "Subtitles",

frontend/public/locales/zh-CN/application.json

@@ -230,6 +230,7 @@
     "color": "颜色",
     "fontSize": "字体大小",
     "disableSubtitle": "禁用字幕",
+    "loop": "循环播放",
     "noSubtitle": "没有在当前目录下找到 ASS/SRT/VTT 字幕文件。",
     "subtitleStyles": "字幕样式",
     "subtitles": "字幕",

frontend/src/component/Viewers/Video/VideoViewer.tsx

@@ -469,6 +469,26 @@ const VideoViewer = () => {
                 fontSize: `${subtitleStyle.fontSize ?? 20}px`,
               },
             },
+            settings: [
+              {
+                name: "loop",
+                html: t("application:fileManager.loop"),
+                switch: false,
+                mounted(item: any) {
+                  const enabled = this.storage.get("loop") === true;
+                  if (enabled) {
+                    item.switch = true;
+                    this.loop = true;
+                  }
+                },
+                onSwitch(item: any) {
+                  const next = !item.switch;
+                  this.loop = next;
+                  this.storage.set("loop", next);
+                  return next;
+                },
+              },
+            ],
             plugins: [],
             lang: t("artPlayerLocaleCode", { ns: "common" }), // TODO: review
           }}