calibration: operator visibility for applied loosenings — live floor + history on the internal calibration surface

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Problem

Applied loosenings write calibration.satisfaction_floor_loosened audit events (#8121 narrow start), but no operator surface shows the applied-override history or the CURRENT live floor — an operator has to query D1 by hand to know whether the system has self-loosened.

Requirements

⚠️ Required pattern. Extend /v1/internal/calibration-trend (#8113, src/services/rule-calibration-trend.ts) or add a sibling internal read — same INTERNAL_JOB_TOKEN gate, aggregate data only.

• Report: current live floor (override or shipped default), each applied loosening with its timestamp + split verdicts, and the flag state.

Deliverables

• The operator read + tests (auth gate, empty state, applied history)

Links & Resources

#8121 (parent), #8113, src/services/satisfaction-floor-loosening-run.ts (the events/override being surfaced)
maintainer-only — observability for the autonomous loop.

[linear-code]

JSO-5659