Auto-memory: call once on exit for --agent --chat, per-turn for single-shot

When running g3 --agent <name> --chat:
- Skip per-turn memory checkpoint calls (too onerous)
- Call memory checkpoint once when exiting (Ctrl-D)

When running g3 --agent <name> (single-shot):
- Preserve existing behavior: call memory checkpoint after each turn

This keeps the auto-memory feature useful without being intrusive
in interactive agent sessions.

crates/g3-cli/src/interactive.rs

@@ -213,9 +213,12 @@ pub async fn run_interactive<W: UiWriter>(
                     .await;
 
                     // Send auto-memory reminder if enabled and tools were called
+                    // Skip per-turn reminders when from_agent_mode - we'll send once on exit
+                    if !from_agent_mode {
                       if let Err(e) = agent.send_auto_memory_reminder().await {
                         debug!("Auto-memory reminder failed: {}", e);
                       }
+                    }
                 } else {
                     // Single line input
                     let input = line.trim().to_string();
@@ -249,11 +252,14 @@ pub async fn run_interactive<W: UiWriter>(
                     .await;
 
                     // Send auto-memory reminder if enabled and tools were called
+                    // Skip per-turn reminders when from_agent_mode - we'll send once on exit
+                    if !from_agent_mode {
                       if let Err(e) = agent.send_auto_memory_reminder().await {
                         debug!("Auto-memory reminder failed: {}", e);
                       }
                     }
                 }
+            }
             Err(ReadlineError::Interrupted) => {
                 // Ctrl-C pressed
                 if in_multiline {
@@ -285,6 +291,14 @@ pub async fn run_interactive<W: UiWriter>(
     // Save session continuation for resume capability
     agent.save_session_continuation(None);
 
+    // Send auto-memory reminder once on exit when in agent+chat mode
+    // (Per-turn reminders were skipped to avoid being too onerous)
+    if from_agent_mode {
+        if let Err(e) = agent.send_auto_memory_reminder().await {
+            debug!("Auto-memory reminder on exit failed: {}", e);
+        }
+    }
+
     output.print("👋 Goodbye!");
     Ok(())
 }