move render_node() to memory.rs

src/hippocampus/memory.rs

@@ -91,3 +91,10 @@ impl MemoryNode {
         out
     }
 }
+
+/// Render a node to a string: content + deduped footer links.
+/// Used by both the CLI command and agent placeholders.
+pub fn render_node(store: &Store, key: &str) -> Option<String> {
+    crate::hippocampus::memory::MemoryNode::from_store(store, key)
+        .map(|node| node.render())
+}