Feature: Memory Timeline Visualization

[LaansDole]

Problem Statement

The platform has a mature memory subsystem (SimpleMemory, FileMemory, BlackboardMemory) with embedding-based retrieval (FAISS + cosine similarity), chunked embeddings, and JSON persistence via memory_path. However, there is zero visibility into memory state from the frontend.

What Changes

• REST API endpoints to list memory stores and items (from active sessions and persisted files)
• WebSocket memory_updated event with callback hook on MemoryManager
• Frontend Memory Timeline page with store selector, chronological item list, and live mode
• Sidebar navigation entry and route registration

[LaansDole]

Hi @zxrys, I am happy to work on this feature if you approve it