Selectable latency percentile and ECS stopped tasks

Last9 changelog introducing selectable latency percentiles (p50, p95, p99, MAX) on the Performance History service overview, replacing the fixed p95 view. A new degradation filter lets users focus on operations where tail latency is regressing against baseline. Additional improvements include did-you-mean suggestions for MCP tool calls, ECS view now showing stopped and killed tasks alongside running ones, and a fix for the Rehydration GET API returning created_by metadata. Several bug fixes address drop rule overwrites, incorrect rehydration permission blocks, and raw HTML tags appearing in MCP docs.