calibration: capture writers + corpus mappings for the slop and quality gate scores

[JSONbored]

Problem

Epic #8211 track D. The knob registry can only govern knobs whose decisions leave labeled evidence. slopGateMinScore and qualityGateMinScore gate real verdicts today but record no signal.rule_fired events, so no corpus can ever form for them.

Requirements

⚠️ Required pattern. Mirror #8101/#8104's capture wiring exactly: fired events through createSignalStore at the env-bearing gate path with the SAME filter the pure evaluation applies, confidence-equivalent metadata (the actual slop/quality score, normalized to [0,1] — document the normalization beside the writer), best-effort writes that can never affect the verdict, and reversal labeling via the EXISTING override recorders (extend CONFIGURED_GATE_BLOCKER_SIGNAL_CODES only if the audit in #8130's header says these codes qualify — justify either way in the PR).

• One rule id per knob (slop_gate_score, quality_gate_score), fired only when the gate actually evaluated the score (mode ≠ off), targetKey = repo#pr.
• Raw-context posture per the calibration: capture bounded raw context for the remaining isConfiguredGateBlocker codes, excluding secret_leak #8130 audit table: these evaluate computed scores, not raw diff content — record the detection's own detail string as rawSignal, never diff.

Deliverables

• Both writers + reversal-path inclusion, 100% branch on touched src
• Corpus visible in the trend (rule rows appear once events flow)

Test Coverage Requirements

Both firing arms (fired/skipped-by-mode), metadata normalization bounds, override pairing end-to-end via the existing reversal tests' pattern.

Links & Resources

#8211 (epic), src/rules/advisory.ts recordConfiguredGateBlockerSignals (#8104's writer), src/review/signal-tracking-wire.ts

Boundaries

Capture only — no registry entries, no knob movement (the maintainer follow-on owns those).

[linear-code]

JSO-5707