Refactor turn host and session projections

[roackb2]

Summary

• remove the extra ChatTurnHostBridgeBuilder layer and make ConversationEngineHostNormalizer adapt public host callbacks directly into the turn host port
• move persisted turn summary and compacted-session projection behavior into ChatSessionRecords
• simplify preflight success output to a single compacted result plus the prepared session

Validation

• yarn typecheck
• yarn test src/tests/unit/core/chat-turn-runtime.test.ts src/tests/unit/core/chat-turn-persistence.test.ts src/tests/unit/core/chat-turn-memory-maintenance.test.ts src/tests/unit/core/chat-turn-host-normalizer.test.ts src/tests/unit/core/conversation-engine.test.ts src/tests/integration/chat/chat-runtime.test.ts
• yarn lint

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Persist the leased session through preflight save

Pass the leased record into persistPrepared instead of persistedSession; right now preflight acquires a lease (leasedSession) but then saves a session built from the unleased snapshot, so the lease is removed before the agent loop runs. That allows a second submit to pass lease_conflict checks and start concurrently against the same session, which can race and overwrite turn state.

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