Move the hook logic from the memory-search binary into a library module
(poc_memory::memory_search) so poc-hook can call it as a direct function
instead of spawning a subprocess with piped stdin.
Also convert the node render call in surface_agent_cycle from
Command::new("poc-memory render") to a direct crate::cli::node::render_node()
call, eliminating another subprocess.
The memory-search binary remains as a thin CLI wrapper for debugging
(--hook reads from stdin) and inspection (show_seen).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
