refactor(ai): extract updateTorrentStatus from js/app.js (agent)

Moved torrent status update logic to `js/ui/torrentStatusController.js` to improve separation of concerns as per `AGENTS.md`. The controller accepts a `getVideoModal` accessor and an `onRemovePoster` callback to decouple it from direct `videoModal` or `Application` dependencies. Added unit tests in `tests/ui/torrentStatusController.test.mjs`.

js/ui/torrentStatusController.js

@@ -0,0 +1,73 @@
+import { devLogger } from "../utils/logger.js";
+
+export default class TorrentStatusController {
+  constructor({ getVideoModal, onRemovePoster }) {
+    if (typeof getVideoModal !== "function") {
+      throw new Error("TorrentStatusController requires a getVideoModal accessor.");
+    }
+    this.getVideoModal = getVideoModal;
+    this.onRemovePoster = typeof onRemovePoster === "function" ? onRemovePoster : () => {};
+  }
+
+  update(torrent) {
+    devLogger.log("[DEBUG] TorrentStatusController.update called with torrent:", torrent);
+
+    if (!torrent) {
+      devLogger.log("[DEBUG] torrent is null/undefined!");
+      return;
+    }
+
+    if (torrent.ready || (typeof torrent.progress === "number" && torrent.progress > 0)) {
+      // Belt-and-suspenders: if WebTorrent reports progress but the DOM events
+      // failed to fire we still rip off the loading GIF. This regression has
+      // bitten us in past releases, so the extra clear is intentional.
+      this.onRemovePoster(
+        torrent.ready ? "torrent-ready-flag" : "torrent-progress"
+      );
+    }
+
+    // Log only fields that actually exist on the torrent:
+    devLogger.log("[DEBUG] torrent.progress =", torrent.progress);
+    devLogger.log("[DEBUG] torrent.numPeers =", torrent.numPeers);
+    devLogger.log("[DEBUG] torrent.downloadSpeed =", torrent.downloadSpeed);
+    devLogger.log("[DEBUG] torrent.downloaded =", torrent.downloaded);
+    devLogger.log("[DEBUG] torrent.length =", torrent.length);
+    devLogger.log("[DEBUG] torrent.ready =", torrent.ready);
+
+    const videoModal = this.getVideoModal();
+
+    // Use "Complete" vs. "Downloading" as the textual status.
+    if (videoModal) {
+      const fullyDownloaded = torrent.progress >= 1;
+      if (typeof videoModal.updateStatus === "function") {
+        videoModal.updateStatus(fullyDownloaded ? "Complete" : "Downloading");
+      }
+
+      if (typeof videoModal.updateProgress === "function") {
+        const percent = (torrent.progress * 100).toFixed(2);
+        videoModal.updateProgress(`${percent}%`);
+      }
+
+      if (typeof videoModal.updatePeers === "function") {
+        videoModal.updatePeers(`Peers: ${torrent.numPeers}`);
+      }
+
+      if (typeof videoModal.updateSpeed === "function") {
+        const kb = (torrent.downloadSpeed / 1024).toFixed(2);
+        videoModal.updateSpeed(`${kb} KB/s`);
+      }
+
+      if (typeof videoModal.updateDownloaded === "function") {
+        const downloadedMb = (torrent.downloaded / (1024 * 1024)).toFixed(2);
+        const lengthMb = (torrent.length / (1024 * 1024)).toFixed(2);
+        videoModal.updateDownloaded(
+          `${downloadedMb} MB / ${lengthMb} MB`
+        );
+      }
+
+      if (torrent.ready && typeof videoModal.updateStatus === "function") {
+        videoModal.updateStatus("Ready to play");
+      }
+    }
+  }
+}