refactor: remove legacy data compatibility

src/sessions/transcriptStore.ts

@@ -43,6 +43,9 @@ type SessionTranscriptContext = {
   sessionId: string;
 };
 
+const DEFAULT_SEARCH_MAX_RESULTS = 8;
+const DEFAULT_SEARCH_MAX_QUERY_CHARS = 240;
+
 export class SessionTranscriptStore {
   private readonly writeQueues = new Map<string, Promise<void>>();
 
@@ -62,6 +65,7 @@ export class SessionTranscriptStore {
   ) {
     const key = this.filePath(context);
     return this.serializeWrite(key, async () => {
+      // 同一会话的多次写入串行化，防止流式结束和 UI 同步同时写同一个 transcript。
       const transcript = (await this.readTranscript(context)) ?? {
         actorKey: context.actorKey,
         clientSessionId: context.clientSessionId,
@@ -82,6 +86,7 @@ export class SessionTranscriptStore {
         lastTurn?.userMessage === userMessage &&
         lastTurn.assistantMessage === assistantMessage
       ) {
+        // 相同问答重复写入时只更新工具调用数量，避免刷新/重试造成 transcript 重复膨胀。
         lastTurn.toolCallCount = Math.max(lastTurn.toolCallCount, turn.toolCallCount);
         transcript.clientSessionId = context.clientSessionId ?? transcript.clientSessionId;
         transcript.sessionId = context.sessionId;
@@ -129,6 +134,7 @@ export class SessionTranscriptStore {
   ) {
     const sourceTranscript = await this.readTranscript(sourceContext);
     const timestamp = new Date().toISOString();
+    // 分叉会话只复制用户选择保留的上下文，后续新分支拥有独立 transcript 文件。
     const nextTranscript: SessionTranscriptRecord = {
       actorKey: targetContext.actorKey,
       clientSessionId: targetContext.clientSessionId,
@@ -144,9 +150,10 @@ export class SessionTranscriptStore {
   async search(
     context: Pick<SessionTranscriptContext, "actorKey" | "projectKey">,
     query: string,
-    maxResults = config.SESSION_SEARCH_MAX_RESULTS,
+    maxResults = DEFAULT_SEARCH_MAX_RESULTS,
   ): Promise<SessionSearchHit[]> {
-    const normalizedQuery = query.trim().toLowerCase().slice(0, config.SESSION_SEARCH_MAX_QUERY_CHARS);
+    // 当前搜索是轻量本地文本匹配，按 actor/project 过滤后再计算简单相关性分数。
+    const normalizedQuery = query.trim().toLowerCase().slice(0, DEFAULT_SEARCH_MAX_QUERY_CHARS);
     if (!normalizedQuery) {
       return [];
     }
@@ -189,38 +196,7 @@ export class SessionTranscriptStore {
   }
 
   private async readTranscript(context: SessionTranscriptContext) {
-    const direct = await readJsonFile<SessionTranscriptRecord>(this.filePath(context));
-    if (direct) {
-      return direct;
-    }
-
-    const clientSessionId = context.clientSessionId?.trim();
-    if (!clientSessionId) {
-      return null;
-    }
-
-    const files = await listJsonFiles(this.baseDir);
-    const matches: SessionTranscriptRecord[] = [];
-    for (const file of files) {
-      const transcript = await readJsonFile<SessionTranscriptRecord>(file);
-      if (!transcript) {
-        continue;
-      }
-      if (
-        transcript.actorKey !== context.actorKey ||
-        transcript.projectKey !== context.projectKey ||
-        transcript.clientSessionId !== clientSessionId
-      ) {
-        continue;
-      }
-      matches.push(transcript);
-    }
-
-    if (matches.length === 0) {
-      return null;
-    }
-
-    return matches.sort((left, right) => right.updatedAt.localeCompare(left.updatedAt))[0] ?? null;
+    return await readJsonFile<SessionTranscriptRecord>(this.filePath(context));
   }
 
   private filePath(context: SessionTranscriptContext) {