chore: add debug logging for OpenAI E2E failure (#715)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: FL4TLiN3

e2e/perstack-cli/providers.test.ts

@@ -31,10 +31,20 @@ describe.concurrent("LLM Providers", () => {
         provider,
       })
       const result = withEventParsing(cmdResult)
+      const seqResult = assertEventSequenceContains(result.events, ["startRun", "completeRun"])
+      if (!seqResult.passed) {
+        process.stderr.write(
+          `[DEBUG ${provider}] exitCode=${result.exitCode} eventTypes=${JSON.stringify(result.events.map((e) => e.type))} seqMsg=${seqResult.message}\n`,
+        )
+        process.stderr.write(
+          `[DEBUG ${provider}] stdout.length=${result.stdout.length} first500=${result.stdout.slice(0, 500)}\n`,
+        )
+        process.stderr.write(
+          `[DEBUG ${provider}] stderr.length=${result.stderr.length} stderr=${result.stderr.slice(0, 500)}\n`,
+        )
+      }
       expect(result.exitCode).toBe(0)
-      expect(assertEventSequenceContains(result.events, ["startRun", "completeRun"]).passed).toBe(
-        true,
-      )
+      expect(seqResult.passed).toBe(true)
       const completeEvent = result.events.find((e) => e.type === "completeRun")
       expect(completeEvent).toBeDefined()
       expect((completeEvent as { text?: string }).text).toBeDefined()