dashboard: msgflow uses shared terminal + backfill via /messages/history

hive-c0re/src/broker.rs

@@ -129,6 +129,36 @@ impl Broker {
             .map_err(Into::into)
     }
 
+    /// Latest `limit` messages across every recipient, newest-first.
+    /// Backs the dashboard's message-flow backfill so a reload doesn't
+    /// blank the operator's view of recent traffic. Returns each row as
+    /// a [`MessageEvent::Sent`] so the dashboard's live renderer (which
+    /// already speaks `MessageEvent`) can replay history through the
+    /// same code path. We don't synthesise `Delivered` events here —
+    /// the recv-side acks live in a different table column and would
+    /// double-render on backfill; the live stream picks them up
+    /// immediately on the first new `recv`.
+    pub fn recent_all(&self, limit: u64) -> Result<Vec<MessageEvent>> {
+        let conn = self.conn.lock().unwrap();
+        let limit_i = i64::try_from(limit.min(i64::MAX as u64)).unwrap_or(i64::MAX);
+        let mut stmt = conn.prepare(
+            "SELECT sender, recipient, body, sent_at
+               FROM messages
+              ORDER BY id DESC
+              LIMIT ?1",
+        )?;
+        let rows = stmt.query_map(params![limit_i], |row| {
+            Ok(MessageEvent::Sent {
+                from: row.get(0)?,
+                to: row.get(1)?,
+                body: row.get(2)?,
+                at: row.get(3)?,
+            })
+        })?;
+        rows.collect::<rusqlite::Result<Vec<_>>>()
+            .map_err(Into::into)
+    }
+
     /// Number of undelivered messages addressed to `recipient`. Non-mutating
     /// — used by the harness to surface "N unread" in tool-result status
     /// lines without popping the queue.