loopd: [heartbeat] table and summarise name check

Co-Authored-By: ornith-1.5-35b-a3b <agent@wntrmute.dev>

crates/loopd/src/config.rs

@@ -177,6 +177,8 @@ pub struct Config {
     pub memory: Memory,
     #[serde(default)]
     pub compact: Compact,
+    #[serde(default)]
+    pub heartbeat: Heartbeat,
 }
 
 /// `[memory]`: `memoryd`'s socket for `loopd` (M5a spec, section 9). An empty path means the
@@ -207,6 +209,24 @@ impl Default for Compact {
     }
 }
 
+/// `[heartbeat]`: how often the standing `heartbeat` session runs (M5d spec, section 4.1).
+/// `every_s` 0 disables it.
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[serde(deny_unknown_fields, default)]
+pub struct Heartbeat {
+    pub every_s: u64,
+    pub prompt: std::path::PathBuf,
+}
+
+impl Default for Heartbeat {
+    fn default() -> Self {
+        Self {
+            every_s: 0,
+            prompt: std::path::PathBuf::from("heartbeat.md"),
+        }
+    }
+}
+
 #[derive(Debug)]
 pub enum ConfigError {
     Read(std::path::PathBuf, std::io::Error),
@@ -235,6 +255,7 @@ impl Config {
             toml::from_str(&text).map_err(|e| ConfigError::Parse(path.to_path_buf(), e))?;
         if let Some(parent) = path.parent() {
             config.baseline.system = parent.join(&config.baseline.system);
+            config.heartbeat.prompt = parent.join(&config.heartbeat.prompt);
         }
         Ok(config)
     }
@@ -259,4 +280,19 @@ impl Config {
     pub fn compact_prompt(&self) -> std::path::PathBuf {
         self.baseline.system.with_file_name("compact.md")
     }
+
+    /// The heartbeat prompt, already joined to the config file's directory by `load`.
+    pub fn heartbeat_prompt(&self) -> std::path::PathBuf {
+        self.heartbeat.prompt.clone()
+    }
+
+    /// Unknown `[compact] summarise` names are a config error (M5d spec, section 4.3).
+    pub fn check_summarise(&self, registry: &crate::tools::Registry) -> Result<(), String> {
+        for name in &self.compact.summarise {
+            if registry.get(name).is_none() {
+                return Err(format!("[compact] summarise: unknown tool {name}"));
+            }
+        }
+        Ok(())
+    }
 }

crates/loopd/src/main.rs

@@ -58,6 +58,11 @@ fn run_selftest(path: &Path) -> ExitCode {
         }
     };
 
+    if let Err(e) = cfg.check_summarise(&loopd::tools::Registry::m5c()) {
+        eprintln!("loopd: {e}");
+        return ExitCode::from(1);
+    }
+
     let client = Client::new(cfg);
     match run_selftest_check(&client) {
         Ok(()) => ExitCode::SUCCESS,
@@ -74,6 +79,11 @@ fn run_serve(path: &Path) -> ExitCode {
         }
     };
 
+    if let Err(e) = cfg.check_summarise(&loopd::tools::Registry::m5c()) {
+        eprintln!("loopd: {e}");
+        return ExitCode::from(1);
+    }
+
     // One loopd per home (M5b spec, section 9a). The lock comes before the socket is touched and
     // before the self-test, so a second copy neither takes the socket of the one that runs nor
     // sends its slot a prompt. Held until the process ends.