Freeze Lane Authority v2 architecture and baseline

[yvette-carlisle]

Summary

• freeze the Lane Authority v2 root-eradication architecture for duplicated project, lane, lifecycle, and effect authority
• define the one-shot v12-to-v2 cutover, quarantine, broker, effect journal, supersession, and tamper-evident telemetry contracts
• add executable C0 inventories for 3,332 source/config files, 104 effect kinds, and 129 scenario/test bindings
• add anti-drift negative controls for ignored source paths and independent scenario-set freezing

This is checkpoint C0 only. It intentionally changes no runtime behavior. C1I verifier-only work starts in a separate PR after this baseline lands. PR #1073 remains superseded and must not merge.

Authority

• XY-1251
• replaces the architectural direction behind XY-1248, XY-1249, and XY-1250 without patch-landing XY-1248: Decodex should close or supersede retained PRs when a repair PR lands the same lane #1073

Validation

• cargo make check: 1,657/1,657 tests passed, one repository-declared skip
• scripts/verify_lane_authority_v2_baseline.sh
• git diff --check plus no-index checks for every new file
• ignored-source and scenario-freeze negative controls
• fresh exact-tree skeptic review: READY, 0 blocker / 0 high / 0 medium / 0 low