loopd: the memory block from memoryd, recall and memory as core tools

Implemented-By: OpenCode session (model recorded in docs/implementer-log.md)

crates/loopd/src/config.rs

@@ -173,6 +173,16 @@ pub struct Config {
     pub baseline: Baseline,
     #[serde(default)]
     pub broker: Broker,
+    #[serde(default)]
+    pub memory: Memory,
+}
+
+/// `[memory]`: `memoryd`'s socket for `loopd` (M5a spec, section 9). An empty path means the
+/// default under `home`.
+#[derive(Debug, Clone, PartialEq, Eq, Default, Deserialize)]
+#[serde(deny_unknown_fields, default)]
+pub struct Memory {
+    pub socket: std::path::PathBuf,
 }
 
 #[derive(Debug)]
@@ -206,6 +216,15 @@ impl Config {
         }
         Ok(config)
     }
+    /// `memoryd`'s socket for `loopd`.
+    pub fn memory_socket(&self) -> std::path::PathBuf {
+        if self.memory.socket.as_os_str().is_empty() {
+            self.paths.home.join("run/loop-memory/memory.sock")
+        } else {
+            self.memory.socket.clone()
+        }
+    }
+
     pub fn channel_socket(&self) -> std::path::PathBuf {
         if self.channel.socket.as_os_str().is_empty() {
             self.paths.home.join("run/loop/loop.sock")