Session-aware REPL for NanoClaw v2 with persistent markdown storage and dynamic skill loading.

• ›Eight core commands: model switching, skill loading, session branching, cross-session search, history compaction, and export to multiple formats (md/json/txt)
• ›Markdown-backed sessions enable persistent state, version control compatibility, and human-readable session history
• ›Designed for zero external runtime dependencies and deterministic, local command handling to maintain simplicity and p