v0.3.1 — automatic rate-limit retry

Fixed

• Burst edits no longer die with opaque timeouts. Wanderlog rate-limits rapid itinerary edits (~9 ops in quick succession) — exactly what an LLM does when building a full trip. The server's rejection frame was being silently dropped, so each affected edit failed with a 10-second "Submit op timeout". Mutations now retry automatically with backoff (2s/4s/8s) and wait out the rate-limit window.
• Rate-limit rejections that exhaust retries surface as a clear rate_limited error instead of a hang.
• Day sections created by wanderlog_update_trip_dates now match Wanderlog's native section shape exactly (added the text field real sections carry).

Full Changelog: v0.3.0...v0.3.1