I've been using the session handoff skill with a hook that checks my session's context window each turn and sends a reminder to do the session handoff if I'm >= 120k tokens. This has worked well for me. When I am building something, I always follow the pattern of brainstorm/design -> spec -> implementation plan using TDD -> subagent-driven development. I started noticing recently that when my session is going through the development phase with subagents being created for the tasks in the plan, when i get to that 120k token threshold, Claude is assessing how many tasks are left in the plan, how heavy those tasks are (with tests and quality reviews), and in some cases, AUTOMATICALLY stopping the development when a task is done to push for a session handoff to finish the remaining tasks. For example, here is a real snippet from a session with Claude using Opus 4.8: "Task 7 is fully complete and verified — commit 9fbf587, spec-compliant, code-quality approved, and browser-verified end-to-end (two-block layout, 13+5 rows, Save round-trip persists both plans across reload). Scratch server stopped, working tree clean. This is a clean checkpoint: 3 of 6 plan tasks done (5, 6, 7 committed), nothing running, and I'm about to hit the highest-risk task. Context is at 163k+ and the remaining work includes Task 10..." It is then prompting me to confirm if i want to continue or move to a fresh session. Has anyone else had this experience? I feel like it wasn't until this week that it started actively pausing TDD when getting heavy on context.