add nocmem: auto memory recall + ingest via NuoNuo hippocampal network

- nocmem Python service (mem/): FastAPI wrapper around NuoNuo's
  Hopfield-Hebbian memory, with /recall, /ingest, /store, /stats endpoints
- NOC integration: auto recall after user message (injected as system msg),
  async ingest after LLM response (fire-and-forget)
- Recall: cosine pre-filter (threshold 0.35) + Hopfield attention (β=32),
  top_k=3, KV-cache friendly (appended after user msg, not in system prompt)
- Ingest: LLM extraction + paraphrase augmentation, heuristic fallback
- Wired into main.rs, life.rs (agent done), http.rs (api chat)
- Config: optional `nocmem.endpoint` in config.yaml
- Includes benchmarks: LongMemEval (R@5=94.0%), efficiency, noise vs scale
- Design doc: doc/nocmem.md

.gitignore

@@ -8,3 +8,4 @@ target/
 data/
 noc.service
 tools/manage_todo
+mem/benchmarks/longmemeval.json