`coach.budget.exceeded` (per-user daily token cap, returned as JSON
429) now surfaces the dedicated "Daily limit reached; resets at 00:00
UTC." copy. `coach.provider.rate_limited` (every provider in the
fallback chain landed on 429, streamed as an SSE error frame) surfaces
"Provider temporarily rate-limited; retry in ~5 min." Other provider
failures keep the generic copy. The chat route emits the new
rate-limited code; the send hook decodes the JSON 429 envelope's
structured `error` field so the drawer can route the bubble copy.
Marc-André Bombeck
b50ebccf0b