[Bug] Rewinding to early conversation point causes context injection dump instead of assistant response

Bug Description
On Claude Fable 5, rewinding to an early point in the conversation reliably makes the next response a dump of injected context (MCP instructions, skill tables, system-reminders) instead of an answer. Session JSONL shows: rewound user turn branches from a near-root parentUuid, startup context deltas are re-injected byte-identical, bridge-session lastSequenceNum stays 0, and the assistant reply has no thinking block, no tool use, and starts mid-sentence inside context material. Does not reproduce on Opus/Sonnet (no bridge-session records).

Environment Info

• Platform: darwin
• Terminal: vscode
• Version: 2.1.210
• Feedback ID: 5f800810-bb1c-4c36-ac0f-f8295de17954

Errors

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