fix: use process.exitCode instead of process.exit() so runner finally blocks clean up temp files

[kevinWangSheng]

What

Replace process.exit(N) with process.exitCode = N; return inside try/finally blocks in all five runners: claude, openai, crewai, nanobot, openclaw.

Why

process.exit() terminates Node.js immediately without running any pending finally blocks. Every runner in this project follows the same pattern:

try {
  const result = spawnSync(...);
  if (result.error) {
    process.exit(1); // finally SKIPPED
  }
  process.exit(result.status ?? 0); // finally SKIPPED
} finally {
  unlinkSync(tmpFile); // never executes
}

Because the finally block is skipped, temporary files written to /tmp — including system prompt content, agent configs, and API credentials passed via environment — are left on disk indefinitely after every invocation.

Using process.exitCode = N; return lets the finally block execute first, removing all temporary files, and then the process exits naturally with the set exit code.

Affected runners:

• src/runners/claude.ts — system prompt + hooks settings JSON in /tmp
• src/runners/openai.ts — generated Python script in /tmp
• src/runners/crewai.ts — generated YAML config in /tmp
• src/runners/nanobot.ts — config dir + system prompt file in /tmp
• src/runners/openclaw.ts — full workspace directory in /tmp

How Tested

• npm run build passes
• gitagent validate passes on example agents
• Manual testing (describe below)

Manually confirmed that after gitagent run completes, no leftover /tmp/gitagent-* files remain.

Checklist

• My code follows the existing style of this project
• I have added/updated tests (if applicable)
• I have updated documentation (if applicable)
• I have read the CONTRIBUTING.md

[shreyas-lyzr]

Reviewed and merged. Correct fix — process.exit() skips the event loop and bypasses finally blocks, leaving temp directories behind. process.exitCode + return lets the finally cleanup run before Node exits. Applied consistently across 5 runners.