fix(embed): implement robust EmbedPlayerModal and guard resetTorrentStats

- Add `js/ui/components/EmbedPlayerModal.js` to implement the `VideoModal` interface for embed contexts (including `resetStats`).
- Update `js/ui/ModalManager.js` to detect embed mode and use `EmbedPlayerModal`.
- Clean up `js/embed.js` to remove local modal definition and add `postMessage` diagnostic logging.
- Update `js/app.js` `resetTorrentStats` log message and verify guard.
- Add unit tests for `EmbedPlayerModal` and `resetTorrentStats` logic.
- Add E2E reproduction script `tests/e2e/repro_issue.spec.ts`.

js/ui/components/EmbedPlayerModal.js

@@ -0,0 +1,106 @@
+export class EmbedPlayerModal {
+  constructor({ document: doc, logger } = {}) {
+    this.document = doc || (typeof document !== "undefined" ? document : null);
+    this.logger = logger || console;
+    this.root = null;
+    this.video = null;
+    this.status = null;
+    this.eventTarget = new EventTarget();
+
+    this.toneClasses = {
+      default: "text-muted",
+      error: "text-danger",
+      success: "text-success",
+    };
+  }
+
+  load() {
+    if (this.document) {
+      this.root = this.document.getElementById("embedRoot");
+      this.video = this.document.getElementById("embedVideo");
+      this.status = this.document.getElementById("embedStatus");
+    }
+    return Promise.resolve(this.root);
+  }
+
+  getRoot() {
+    return this.root;
+  }
+
+  getVideoElement() {
+    return this.video;
+  }
+
+  setVideoElement(videoElement) {
+    if (videoElement) {
+      this.video = videoElement;
+    }
+    return this.video;
+  }
+
+  resetStats() {
+    // no-op for embed view
+  }
+
+  setStatus(message, tone = "default") {
+    if (!this.status) {
+      return;
+    }
+
+    const normalizedMessage = typeof message === "string" ? message.trim() : "";
+    this.status.textContent = normalizedMessage;
+
+    Object.values(this.toneClasses).forEach((className) => {
+      if (className) {
+        this.status.classList.remove(className);
+      }
+    });
+
+    const toneClass = this.toneClasses[tone] || this.toneClasses.default;
+    if (toneClass) {
+      this.status.classList.add(toneClass);
+    }
+  }
+
+  updateStatus(message) {
+    this.setStatus(message, "default");
+  }
+
+  applyLoadingPoster() {
+    this.setStatus("Preparing playback…", "default");
+  }
+
+  forceRemovePoster() {
+    return false;
+  }
+
+  clearPosterCleanup() {}
+
+  setTorrentStatsVisibility(isVisible) {
+    if (!this.root) {
+      return;
+    }
+    this.root.dataset.torrentStats = isVisible ? "true" : "false";
+  }
+
+  open() {
+    return this.root;
+  }
+
+  close() {}
+
+  updateMetadata() {}
+  setShareEnabled() {}
+
+  addEventListener(type, listener, options) {
+    this.eventTarget.addEventListener(type, listener, options);
+  }
+
+  removeEventListener(type, listener, options) {
+    this.eventTarget.removeEventListener(type, listener, options);
+  }
+
+  dispatch(type, detail) {
+    return this.eventTarget.dispatchEvent(new CustomEvent(type, { detail }));
+  }
+}