0a98aa252b
- Clear inherited todo list state and persist empty edit at fork creation to prevent parent task reminders from affecting the tangential session. - Re-inject the fork notice after each auto-compaction event to ensure the boundary between the parent and child session survives history summarization. - Align the provider cache key with the parent's actual pinned key to correctly mirror cached session context. - Update `AgentSession` to perform a full entry rewrite during tool result pruning to ensure session files match pruned state for reliable resuming and branching.