manager mcp: expose 'remind' tool sharing storage helper with agent surface

hive-c0re/src/agent_server.rs

@@ -227,30 +227,32 @@ fn handle_remind(
     timing: &hive_sh4re::ReminderTiming,
     file_path: Option<&str>,
 ) -> AgentResponse {
-    let due_at = match resolve_due_at(timing) {
-        Ok(t) => t,
-        Err(e) => {
-            return AgentResponse::Err {
-                message: format!("invalid reminder timing: {e:#}"),
-            };
-        }
-    };
-    let (stored_message, stored_path) = match prepare_remind_storage(agent, message, file_path) {
-        Ok(pair) => pair,
-        Err(e) => return AgentResponse::Err { message: e },
-    };
-    match coord
+    match store_remind(coord, agent, message, timing, file_path) {
+        Ok(()) => AgentResponse::Ok,
+        Err(message) => AgentResponse::Err { message },
+    }
+}
+
+/// Shared remind-storage path used by both the agent and the manager
+/// dispatchers. Validates timing, applies the auto-file overflow
+/// dance (see [`prepare_remind_storage`]), and writes the reminder
+/// row. Returns `Ok(())` on success, or a caller-ready error string
+/// the dispatcher wraps in `*Response::Err`.
+pub(crate) fn store_remind(
+    coord: &Arc<Coordinator>,
+    agent: &str,
+    message: &str,
+    timing: &hive_sh4re::ReminderTiming,
+    file_path: Option<&str>,
+) -> Result<(), String> {
+    let due_at = resolve_due_at(timing).map_err(|e| format!("invalid reminder timing: {e:#}"))?;
+    let (stored_message, stored_path) = prepare_remind_storage(agent, message, file_path)?;
+    let id = coord
         .broker
         .store_reminder(agent, &stored_message, stored_path.as_deref(), due_at)
-    {
-        Ok(id) => {
-            tracing::info!(%id, %agent, %due_at, "reminder scheduled");
-            AgentResponse::Ok
-        }
-        Err(e) => AgentResponse::Err {
-            message: format!("failed to store reminder: {e:#}"),
-        },
-    }
+        .map_err(|e| format!("failed to store reminder: {e:#}"))?;
+    tracing::info!(%id, %agent, %due_at, "reminder scheduled");
+    Ok(())
 }
 
 /// Decide what we actually store in the reminders row, applying the