feat: enhance monitor info with live status, summary metrics, and assertions (#20)
- Fix missing fields in httpMonitorToLocal/tcpMonitorToLocal (DegradedAfter, Body, Headers, Assertions) - Add parallel GetMonitorStatus and GetMonitorSummary RPC calls with graceful degradation - Display global status (active/degraded/error) color-coded in config table - Add per-region status table with provider labels - Add summary metrics table (success/degraded/failed counts, P50-P99 latency, last ping) - Add assertions table for HTTP monitors - Add --time-range flag (1d/7d/14d) for summary period selection - New JSON output wrapper struct with monitor, status, regions, and summary sections Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>