mcp_server.py never calls configure_harness, so it resolved ~/.mem0/mem0-plugin while the Cursor, Kimi and Antigravity hooks use ~/.mem0/<host>-plugin. A key set in Cursor's plugin settings and cached by the sessionStart hook was invisible to search_memories. build.py now writes DATA_DIR_NAME into each bundle's _harness_id.py and memory_core seeds its default from it, like the PLATFORM_* values.
An end-to-end test launches the real session-start hook and MCP server for Claude Code, Cursor and Codex the way each host does, with the key in plugin settings and in the mem0 init config, and checks the search reaches the API with that key.
Bumps the Python plugins to 0.3.4, OpenCode to 0.4.2, Pi and DeepSeek to 0.3.3, with changelog entries for each.
Fixes#7346
kartik-mem0