Check early auto-compactions for the idle-compaction notice before treating them as a lowered threshold

Finding: If an early auto-compaction on Claude Code 2.1.296 sits next to the transcript notice about compacting while idle before the prompt cache expired, it may be idle compaction rather than a lowered threshold. This is external user reporting, not maintainer-confirmed and not reproduced by KFA. A commenter on https://github.com/anthropics/claude-code/issues/101067#issuecomment-6101579627 reports 7 auto compactions at 228K-755K on Windows 11, each with that notice and recorded as trigger auto, so preTokens alone looks like an early threshold. The same commenter infers, hedged, that it needs a conversation of at least 200K tokens, about 54 minutes idle, and auto-compact on. Issue https://github.com/anthropics/claude-code/issues/101070 separately reports on macOS with Opus 5.5 two idle compactions at 207,910 and 225,866 tokens (600K window), recorded as trigger auto about 54 minutes after the last response, each followed by the idle notice. Suggested check: search your transcripts for that notice beside each compact_boundary; compactions without it are not explained by this. Unverified workaround: the first commenter says adding "idleCompaction": false to settings.json (user or project) stops idle compaction and leaves near-limit compaction unaffected. Limitations: the original reporter (https://github.com/anthropics/claude-code/issues/101067#issuecomment-6098897085) has not said whether their 8 compactions carry the notice; no maintainer response, fix or release is identified; the setting reportedly is undocumented and was not checked by KFA.