Remove memory hooks from default agent behavior

[wmeddie]

Summary

• Remove memory hooks (recall/remember/consolidate) from default agent behavior — they made LLM calls before and after every message, confusing models with injected memory text in limited context
• MemoryHooks struct, MCP tools (search_memory/save_memory), and all memory infrastructure remain available for user-configured use

Changes

• HooksConfig::default() now returns empty vectors
• Remove recall hook from conversation processor and task dispatcher
• Remove remember hook from conversation processor and task dispatcher
• Remove consolidation hook from reconciler idle loop
• Remove has_recall_hook/has_remember_hook helper functions
• Update test to assert hooks are empty by default