XY-843: [ELF benchmark suite] Add trust, source-of-truth, and personalization cases

[yvette-carlisle]

Summary

• Add real_world_memory fixtures for trust/source-of-truth rebuild, TTL/delete staleness, redaction/private exclusion, and scoped personalization.
• Extend the real_world_job report with evidence, source-ref, quote, stale retrieval, scope, redaction, and Qdrant rebuild counters.
• Add cargo make real-world-memory plus tests and benchmark docs.

Validation

• cargo make real-world-job-smoke
• cargo make real-world-memory
• cargo nextest run -p elf-eval --test real_world_job_benchmark --all-features
• cargo make fmt
• cargo make lint-fix
• cargo make checks