Add dreaming review queue

[yvette-carlisle]

Summary

• Add elf.dreaming_review_queue/v1 over consolidation proposals with variants, affected refs, policy, and review audit readback.
• Expose the queue through admin HTTP and MCP (elf_dreaming_review_queue).
• Add benchmark evidence/report docs for XY-1021 covering memory summary, proactive brief, scheduled memory, tag, duplicate merge, page rebuild, memory promotion, graph fact, and correction variants.

Validation

• cargo test -p elf-service dreaming_review_queue -- --nocapture
• cargo test -p elf-mcp registers_all_tools -- --nocapture
• cargo test -p elf-eval --test real_world_job_benchmark dreaming_review_queue_report_wires_reviewable_policy_contract -- --nocapture
• decodex docs check
• git diff --check
• cargo make check (312 passed, 87 skipped)

Linear: XY-1021