bug(cli): hide internal SSE parser stack trace on parse errors

[Suyash-K]

What version of Codex is running?

Latest

Which model were you using?

o4-mini, gpt-4o

What platform is your computer?

Windows

What steps can reproduce the bug?

Describe the bug
When an SSE parsing error occurs (e.g. insufficient_quota), the CLI prints the raw bundled code around NEWLINE_REGEXP… (dist/cli.js:449), which is noise and not actionable for end users.

To Reproduce

1. Install the latest @openai/codex CLI on Windows/macOS/Linux.
2. Trigger a quota error (e.g., exhaust your plan).
3. Observe the console: you’ll see the low‑level parser code before the error message.

What is the expected behavior?

Expected Behavior

Only a concise system warning should appear instead of confusing and unactionable messages

What do you see instead?

No response

Additional information

No response

[Suyash-K]

Proposed Fix

Wrap the for await (const event of stream) loop in codex-cli/src/utils/agent/agent-loop.ts with a try/catch that intercepts errors matching /NEWLINE_REGEXP/, emits a user-friendly message via this.onItem(...), and returns early.