Handle edge case where Claude's --resume creates an orphan session file
before resuming the original session, leaving two session files pointing
to the same Zellij pane.
The deduplication algorithm (_dedupe_same_pane_sessions) resolves
conflicts by preferring:
1. Sessions with context_usage (indicates actual conversation occurred)
2. Higher conversation_mtime_ns (more recent file activity)
When an orphan is identified, its session file is deleted from disk to
prevent re-discovery on subsequent state collection cycles.
Test coverage includes:
- Keeping session with context_usage over one without
- Keeping higher mtime when both have context_usage
- Keeping higher mtime when neither has context_usage
- Preserving sessions on different panes (no false positives)
- Single session per pane unchanged
- Sessions without pane info unchanged
- Handling non-numeric mtime values defensively
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
19a31a4620