[Bug] Fable 5 reasoning_extraction safeguard false-positive regression blocking legitimate sessions

Bug Description
Fable 5 safeguard false-positive REGRESSION: [reasoning_extraction] blocks 100% of sessions in my personal multi-session monitoring repo. - Since ~2026-08-30 23:04 UTC, every new Claude Code session in my repo "dekadanna-fleet" (a personal harness that monitors my own Claude Code sessions: status board, beacons, unattended-runner config) is blocked on claude-fable-5 with [reasoning_extraction] ("reverse engineering or duplicating model outputs"). - The user message is irrelevant: even a trivial "connectivity test, reply 'OK' only, no tools" prompt is blocked (req_011CeaRRYDxJBgmW764X3a8s). The identical prompt in the same directory succeeds on claude-opus-5. - Trigger seems to be SessionStart-hook-injected context (a daily brief listing harness/monitoring tasks). A session in another repo worked fine until it read the fleet repo's STATUS.md session board mid-conversation; the very next request was refused (2026-08-31 07:09:49 UTC). - The same repo on claude-fable-5 worked with zero refusals through Aug 28. 12+ refusals since Aug 30. Sample request IDs: req_011CeaQQBfJ4VgyQz9wX6Lh9, req_011CeaQuJLSQaURJxsRqTWZa, req_011CeaRRYDxJBgmW764X3a8s. - All content is my own personal task management. Nothing involves extracting model outputs for training or duplication.

Environment Info

• Platform: darwin
• Terminal: Orca
• Version: 2.1.251
• Feedback ID: 069edceb-cce5-46bb-8111-7ec013cd7501

Errors

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