sync from monorepo @ 2452e92e

crates/dirigent_archivist/src/session.rs

@@ -0,0 +1,24 @@
+//! Session management and lineage tracking.
+//!
+//! Handles session metadata, lineage relationships (splits, continuations),
+//! and session lifecycle operations.
+
+use crate::error::Result;
+
+/// Session manager for tracking session metadata and lineage
+pub struct SessionManager {
+    // Placeholder - will be populated in implementation phases
+}
+
+impl SessionManager {
+    /// Create a new session manager
+    pub fn new() -> Result<Self> {
+        Ok(Self {})
+    }
+}
+
+impl Default for SessionManager {
+    fn default() -> Self {
+        Self::new().expect("Failed to create default SessionManager")
+    }
+}