v0.8.12 — Integrity: Launch Boost WRI separation

• Launch Boost no longer modifies displayed WRI scores (+10/+20 point grant removed, per /integrity §11.5)
• Boost value is now purely Pioneer routing traffic share for the boost duration
• Per-result boost_active: true/false field added to search responses for transparent disclosure
• compute_wri_v2 formula updated in both API and rank service — boost_wri_bonus parameter removed
• All ranking pipeline paths verified: WRI is probe/payment-signal derived only