perf_direct

added a direct engine latency benchmark that bypasses Bolt/HTTP entirely.

New test

~/src/NornicDB/scripts/perf_direct/main.go

How to run

Direct Badger (disk writes, no protocol overhead):

go run ./scripts/perf_direct --clean --iterations=100 --mode=badger

Async engine (shows cache‑first writes + explicit flush timing):

go run ./scripts/perf_direct --clean --iterations=100 --mode=async

If you want worst‑case disk latency (fsync on every write):

go run ./scripts/perf_direct --clean --iterations=100 --mode=badger --sync-writes

What it measures

• Single node create
• Batch node create (BulkCreateNodes)
• Node update
• Relationship create
• (Async mode only) flush duration

I also updated the plan doc to reference this new direct‑engine benchmark command.

Want me to add a matching shell wrapper (like the Bolt/HTTP scripts) or collect results into a CSV?