Materialize OpenViking trajectory benchmark evidence

[yvette-carlisle]

Summary

• add a dedicated real-world-memory-context-trajectory cargo-make task for the OpenViking context-trajectory slice
• add the June 19 OpenViking trajectory materialization report and checked-in JSON snapshot
• assert the report, README/index links, and blocked claim boundaries in real_world_job_benchmark tests

Validation

• cargo make real-world-memory-context-trajectory
• jq empty apps/elf-eval/fixtures/report_snapshots/2026-06-19-openviking-trajectory-materialization-report.json
• cargo test -p elf-eval --test real_world_job_benchmark openviking_trajectory_materialization_report_preserves_blocked_gates -- --test-threads=1
• cargo test -p elf-eval --test real_world_job_benchmark context_trajectory_fixtures_report_blocked_openviking_gates -- --test-threads=1
• cargo make fmt-check
• cargo make check-docs
• decodex docs check
• cargo make lint
• cargo make check