opencode run hangs forever on API errors (breaks CLI/automation integrations)

[EivMeyer]

Bug Description

When opencode run encounters an API error (e.g., 429 rate limit), it logs the error but never exits - it hangs indefinitely. This breaks any CLI tool or automation system that spawns opencode as a subprocess.

Reproduction

# With an expired/rate-limited account:
timeout 30 opencode run "what is 1+1"
# Result: hangs for 30 seconds, exit code 124 (timeout)

Expected Behavior

opencode should fail fast with a non-zero exit code and clear error message:

Error: API rate limited (429). Please check your subscription status.
Exit code: 1

Actual Behavior

opencode logs the error internally but continues running forever:

ERROR service=llm error={"statusCode":429,...} 
# Then hangs indefinitely - no exit, no output to user

Impact

This breaks integrations like zeroshot which spawn CLI tools as subprocesses:

// zeroshot spawns opencode
exec('opencode run "task"', (error, stdout) => {
  // This callback NEVER fires because opencode never exits
});

Workaround: We've added timeouts to our subprocess calls, but the real fix should be in opencode.

Environment

• opencode version: 1.1.16
• OS: Linux (Ubuntu 22.04)
• Auth: OpenAI OAuth

Suggested Fix

In the error handling path, ensure the process exits with non-zero code:

if (response.status === 429) {
  console.error('Error: API rate limited. Check subscription status.');
  process.exit(1);  // <-- Currently missing
}

Or more generally: any unrecoverable API error should cause opencode run to exit, not hang.