Brain-AI Memory v0.3.1

Patch release for Smart Connections users. The semantic adapter now keeps one stdio server process alive across queries, so embedding and reranker models stay warm; a live two-query smoke reused the same process and reduced total latency from 5.9 s cold to 1.4 s warm. Adds explicit mcp_env configuration for SMART_SEARCH_PROFILE=adaptive, retains v1/v2 response compatibility, preserves v2 server ranking, and closes failed child connections before local fallback. CI, 16 tests, MCP round-trip, runtime contract 14/14, and 420-record component ablation passed.