Auto-compaction stopped working - conversation fails when manually compacting

Claude Code was previously auto-compacting conversations when approaching context limits, but this behavior stopped working approximately on 2025-10-05.

Current behavior:

1. Conversation grows too long
2. System tells user to run /compact
3. When user runs /compact, it fails because conversation is already too long

Expected behavior:

• Claude Code should automatically compact conversations before reaching critical context limits
• Users should never be in a situation where they're told to compact but compaction fails

Impact:
This appears to be a regression - the auto-compaction feature was working for weeks but suddenly stopped.

Environment:

• Platform: Linux 6.14.0-29-generic
• Claude Code Version: 2.0.8
• Date noticed: ~2025-10-05