XY-862: [ELF benchmark vNext P1] Encode production-ops real-world memory suite

[yvette-carlisle]

Summary

• Add six checked-in production_ops real-world memory fixtures covering backfill resume, restore/cold-start readback, resource envelope, dependency incomplete, missing private manifest blocked, and provider credential boundary blocked states.
• Add cargo make real-world-memory-production-ops and aggregate tests so production_ops is encoded in the real-world memory suite.
• Update benchmark docs to explain what this fixture suite proves and what still requires live/private-corpus validation.

Verification

• cargo make real-world-memory
• cargo make real-world-memory-production-ops
• cargo make fmt
• cargo make lint-fix
• cargo make checks

Semantic drift review: pass. Documentation claims match the new fixture target and runner behavior; the suite does not claim private-corpus, credential-backed, or Docker/live-baseline success.