Missing lesson_delete tool — no way to delete/cleanup lessons via MCP or REST API

[AzYuJie]

Problem

The agentmemory MCP server (53 tools) has memory_lesson_save and memory_lesson_recall for CRUD operations on lessons, but there is no lesson_delete (or equivalent) tool.

• memory_governance_delete only operates on mem_* (memories), not lsn_* (lessons)
• No undocumented REST API endpoints for lesson deletion (DELETE /agentmemory/lesson/:id returns 404)
• The internal KV store supports soft-delete (lesson.deleted = true) as seen in source code, but it is not exposed via any MCP tool

Impact

Users cannot remove duplicate, outdated, or incorrect lessons. This is especially problematic when:

• Multiple lessons cover the same topic (needs consolidation/dedup)
• A lesson was created with incorrect content
• Cleanup of test/experimental lessons

The only workaround is manual KV store manipulation, which is not user-accessible.

Proposed Solution

Expose a memory_lesson_delete MCP tool with:

• Parameter: id (single lesson ID) or ids (comma-separated, matching memory_governance_delete pattern)
• Parameter: reason (audit trail, same as governance_delete)
• Behavior: soft-delete (set deleted = true), matching the existing internal mechanism

Environment

• agentmemory version: latest (npm @agentmemory/agentmemory)
• MCP server ports: 3113/3114
• Verified via: direct REST API probing + MCP tool list + source code inspection