Engram 0.15.11

Fixed

• Keep visualizer node snapshots when a repeated hub insertion leaves membership
  unchanged. Refresh affected hub flags without rebuilding unrelated nodes,
  preserving node edits, deletion and galaxy precedence.
• Include SubagentStop events in the Codex hook-status report.

Diagnostics

• Correlate detached Claude learner starts and exits with their originating
  session, trigger, run and process in the existing session log. Exit status
  describes the process outcome; memory persistence still requires readback.