删除记忆接口返回成功但记忆未实际删除

[Memtensor-AI]

删除一条记忆后接口返回成功，但刷新页面后该记忆仍然存在并可以被检索到，重复删除三次结果相同。预期彻底删除，实际删除未生效。OpenClaw 知识库中已有 delete/memory 接口说明，但当前现象为接口返回 success 但未实际删除，且稳定复现，属于明确的产品 Bug。

[Memtensor-AI]

🤖 AutoDev has picked up this issue and started working on it.

Task ID: b4115f14279d5b84
Working branch: bugfix/autodev-2331-20260902095324632
Target branch: latest dev* branch
Workflow: opsp (analysis → coding → testing → PR)

I will post the PR link here once done. If I need more information, I will ask in the comments.

[Memtensor-AI]

✅ AutoDev task b4115f14279d5b84 completed.

Summary: Fixed bug #2331: delete memory API returned success but the memory remained searchable after deletion.

Root cause: Neo4jCommunityGraphDB.delete_node_by_prams in src/memos/graph_dbs/neo4j_community.py only removed nodes from the Neo4j graph but never purged the corresponding embedding vectors from vec_db (Qdrant). Since all search calls go through vector similarity on vec_db, stale vectors caused deleted memories to keep surfacing in search results. The clear() method and the reorganize path both cleaned vec_db correctly — delete_node_by_prams simply omitted that step.

Fix: replaced the pre-delete count query with an ID-collecting query (MATCH ... RETURN n.id AS id), then called self.vec_db.delete(collected_ids) after the graph DETACH DELETE. A vec_db failure is caught and logged as a warning rather than re-raised, so a transient vector store error does not roll back an already-committed graph deletion. Added 5 regression tests in tests/graph_dbs/test_delete_vec_cleanup.py covering delete-by-memory-ids, delete-by-filter, empty-list early-return, no-args early-return, and vec_db failure resilience. All 5 tests pass; all 36 existing graph_dbs tests continue to pass; ruff lint clean.

Base branch: main
Branch: bugfix/autodev-2331-20260902095324632
Commit: a6d065e
PR: #2332
Assigned to: @whipser030
Reviewers: @MatthewZhuang, @CarltonXiang, @syzsunshine219, @World-controller