fix(transcripts): handle read stream errors gracefully in TranscriptsStore (#100524)

* fix(transcripts): handle read stream errors gracefully in TranscriptsStore

* proof(transcripts): add real behavior proof script for store stream error catch

* fix(transcripts): reject with Error in stream error handler

* proof(transcripts): replace wrapper with real EISDIR stream error proof

* fix(transcripts): reject non-ENOENT stream errors after stream close

scripts/proof/transcripts-store-stream-errors.mts

@@ -0,0 +1,54 @@
+// Real behavior proof: TranscriptsStore rejects non-ENOENT stream errors
+// gracefully instead of leaking an unhandled rejection or returning partial data.
+//
+// The proof creates a real transcript session directory where `transcript.jsonl`
+// is a directory instead of a file. `fs.createReadStream` on a directory emits
+// an EISDIR error on the stream. With the fix, `readUtterancesFromSessionDir`
+// rejects with that error after the stream closes. Missing files (ENOENT) still
+// resolve to an empty array. Before the fix the unhandled stream error would
+// reject the promise before listeners were attached.
+
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+const repoRoot = path.dirname(path.dirname(path.dirname(fileURLToPath(import.meta.url))));
+const { TranscriptsStore } = await import(path.join(repoRoot, "src/transcripts/store.js"));
+
+const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-proof-transcripts-"));
+
+const session = {
+  sessionId: "proof-session",
+  startedAt: "2026-07-01T00:00:00Z",
+};
+
+const store = new TranscriptsStore(tmpDir);
+const sessionDir = store.sessionDir(session);
+await fs.mkdir(sessionDir, { recursive: true });
+
+// Make transcript.jsonl a directory. createReadStream on a directory emits
+// EISDIR, which exercises the stream error handler in readUtterancesFromDir.
+const transcriptPath = path.join(sessionDir, "transcript.jsonl");
+await fs.mkdir(transcriptPath);
+
+console.log("=== Proof: transcripts store stream error catch ===\n");
+console.log(`Created directory-as-file at: ${transcriptPath}`);
+console.log("Calling readUtterancesFromSessionDir with maxUtterances...\n");
+
+try {
+  await store.readUtterancesFromSessionDir(sessionDir, { maxUtterances: 10 });
+  console.log("\nFAIL: readUtterancesFromSessionDir should have rejected for EISDIR.");
+  process.exitCode = 1;
+} catch (err) {
+  const message = err instanceof Error ? err.message : String(err);
+  console.log(`Rejected with: ${message}`);
+  if (message.includes("EISDIR") || message.includes("is a directory")) {
+    console.log("\nPASS: EISDIR stream error was caught and rejected after stream close.");
+  } else {
+    console.log("\nFAIL: unexpected rejection reason.");
+    process.exitCode = 1;
+  }
+} finally {
+  await fs.rm(tmpDir, { recursive: true, force: true });
+}