`ChatRuntime.correct()` propagates a backward perturbation through the
session graph (per session/correction.py): each past turn whose output
versor has non-trivial CGA-alignment with the correction versor is
blended toward it (decayed by graph distance). The forward regen turn
that followed already emitted a TurnEvent — but the backward
perturbation itself was invisible to the telemetry sink.
ADR-0059 closes that gap with a discriminated event line.
- chat/telemetry.py — adds `serialize_correction_event` +
`format_correction_event_jsonl` emitting one JSONL line discriminated
by `"type": "correction"`. Payload: target_turn, records_count,
turns_skipped, turn_idxs_affected, max_delta_norm, mean_delta_norm,
SHA-256 correction_versor_digest, pack ids. No raw versor coordinates.
- chat/runtime.py — `_emit_correction_event` (mirrors
`_emit_turn_event`); called from `correct()` after the graph state
is updated but before the forward regen turn. No-op without sink.
- tests/test_correction_telemetry.py — 7 tests pin: no-op without
sink, emission with sink, payload shape (required keys + types +
ranges), SHA-256 digest shape, trust boundary (no versor
coordinates leaked), determinism (byte-identical lines across
runs), correction event and turn event coexist in the sink.
Trust boundary (per CLAUDE.md):
- Metadata-only: only L2 deltas + SHA-256 digest.
- No implicit wall-clock.
- Deterministic: same CorrectionResult → byte-identical line.
- Sink contract unchanged: `emit(line: str)`.
- `versor_condition < 1e-6` invariant: untouched (telemetry-only).
Verification: smoke 67 / runtime 19 / correction telemetry 7 — green.
