cli: add memory_history, remove dump-json/edges/lookups

- Add memory_history MCP tool for version history
- Convert cmd_history to use memory_rpc
- Add raw parameter to memory_render for editing
- Remove unused: dump-json, list-edges, lookup-bump, lookups
- Fix render_node path in defs.rs/subconscious.rs

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

src/subconscious/defs.rs

@@ -250,7 +250,7 @@ fn resolve(
             let mut text = String::new();
             let mut result_keys = Vec::new();
             for key in keys {
-                if let Some(rendered) = crate::cli::node::render_node(store, key) {
+                if let Some(rendered) = crate::hippocampus::memory::render_node(store, key) {
                     if !text.is_empty() { text.push_str("\n\n---\n\n"); }
                     text.push_str(&format!("## {}\n\n{}", key, rendered));
                     result_keys.push(key.clone());