实现pdf中划句子ai伴读的功能，修复pdf高亮显示的问题

src/modules/lecture/ui/registerSelectionExplainPopup.ts

@@ -1,11 +1,15 @@
 import { config } from "../../../../package.json";
 import { getString } from "../../../utils/locale";
-import { cacheReaderSelection } from "../../pdf/selection";
+import { cacheReaderSelection, getCachedReaderSelectionPosition } from "../../pdf/selection";
 import { highlightTextInPdf } from "../../pdf/readerSync";
 import { getRegularItem, resolvePaperAttachment } from "../infrastructure/zotero/adapter";
 import { paperIdFromCacheKey } from "../infrastructure/pdf/fileHash";
 import { explainSelectionLecture } from "../application/explainSelectionLecture";
-import { playSelectionExplainStandalone } from "../application/playSelectionExplain";
+import {
+  beginSelectionExplainSession,
+  isSelectionExplainSessionActive,
+  playSelectionExplainExclusive,
+} from "../application/playSelectionExplain";
 import { lectureEvents } from "../infrastructure/events";
 
 function tryString(value: unknown): string {
@@ -47,6 +51,7 @@ export async function runSelectionExplainFromReader(
   }
 
   cacheReaderSelection(text);
+  const sessionId = beginSelectionExplainSession();
   showHeadline(getString("lecture-selection-explaining"));
 
   try {
@@ -57,9 +62,12 @@ export async function runSelectionExplainFromReader(
       onProgress: (message) => showHeadline(message),
     });
 
+    if (!isSelectionExplainSessionActive(sessionId)) return;
+
     await highlightTextInPdf(item, {
       text: result.original,
       page: result.page,
+      position: getCachedReaderSelectionPosition(result.original),
     });
 
     lectureEvents.emit("lecture:selection_explain", {
@@ -69,7 +77,9 @@ export async function runSelectionExplainFromReader(
       result,
     });
 
-    await playSelectionExplainStandalone(result);
+    if (!isSelectionExplainSessionActive(sessionId)) return;
+
+    await playSelectionExplainExclusive(result);
     showHeadline(getString("lecture-selection-done"));
   } catch (e) {
     const msg = e instanceof Error ? e.message : String(e);
@@ -96,11 +106,11 @@ export function registerSelectionExplainPopup(): void {
             "toolbar-button wide-button chatpapers-selection-explain-btn";
           btn.textContent = getString("lecture-explain-selection-short");
           btn.title = getString("lecture-explain-selection");
-          btn.addEventListener("click", (ev) => {
+          btn.addEventListener("click", (ev: Event) => {
             ev.preventDefault();
             ev.stopPropagation();
             void runSelectionExplainFromReader(reader, text);
-          });
+          }, { once: true });
           append(btn);
         } catch (e) {
           ztoolkit.log("[ChatPapers:Lecture] selection popup button failed", e);