Workflow agents now wait out rate limits instead of failing

What

• When a spawned workflow agent's API call fails with a rate-limit error, the workflow harness now recognizes it distinctly (an apiError.kind of "rate_limit"), shows the user the quota limits, and waits for the limit to clear before automatically retrying the call, instead of failing immediately.
• If the user declines to wait, the workflow continues with a failure note; if the wait is aborted, or usage-limit waiting is disabled remotely, that's surfaced as a distinct outcome too.
• The status bar/UI gained a "paused statuses" display: a rateLimitWait state shows a warning-colored indicator and pausedStatuses, suppressing the normal phase text while a workflow is paused waiting on a rate limit.

Why

Instead of a workflow agent call failing outright when it hits a rate limit, it now pauses, shows the user why, and resumes automatically once the limit clears, avoiding unnecessary failures.