- Added mental-model settings and config defaults for enablement, auto-seed, refresh interval, and render budget.
- Added built-in mental-model seeds and scope-aware rendering with `<mental_models>` extraction, truncation, and tag handling.
- Added `/memory mm` aliases and handlers for list, show, refresh, history, seed, reload, and delete commands.
- Added client APIs and bootstrap/cache wiring so snippets refresh and inject into prompts on startup.
- Added tests covering seed scope behavior, rendering caps, diffs, and backend/session reload behavior.
