Use agent name as prompt in --agent --chat mode (e.g., "butler>")

Changed run_interactive() parameter from bool to Option<&str> agent_name.
When agent_name is Some, use it as the prompt instead of "g3>".

crates/g3-cli/src/accumulative.rs

@@ -300,7 +300,7 @@ async fn handle_command(
                 chat_combined_content,
                 workspace_dir,
                 cli.new_session,
-                false, // from_agent_mode
+                None, // agent_name (not in agent mode)
             )
             .await?;
 

crates/g3-cli/src/agent_mode.rs

@@ -268,7 +268,7 @@ pub async fn run_agent_mode(
             combined_content,
             &workspace_dir,
             new_session,
-            true,  // from_agent_mode - skip session resume and verbose welcome
+            Some(agent_name),  // agent name for prompt (e.g., "butler>")
         )
         .await;
     }

crates/g3-cli/src/interactive.rs

@@ -16,7 +16,8 @@ use crate::task_execution::execute_task_with_retry;
 use crate::utils::display_context_progress;
 
 /// Run interactive mode with console output.
-/// If `from_agent_mode` is true, skip session resume and verbose welcome (agent_mode already printed context info).
+/// If `agent_name` is Some, we're in agent+chat mode: skip session resume/verbose welcome,
+/// and use the agent name as the prompt (e.g., "butler>").
 pub async fn run_interactive<W: UiWriter>(
     mut agent: Agent<W>,
     show_prompt: bool,
@@ -24,9 +25,10 @@ pub async fn run_interactive<W: UiWriter>(
     combined_content: Option<String>,
     workspace_path: &Path,
     new_session: bool,
-    from_agent_mode: bool,
+    agent_name: Option<&str>,
 ) -> Result<()> {
     let output = SimpleOutput::new();
+    let from_agent_mode = agent_name.is_some();
 
     // Check for session continuation (skip if --new-session was passed or coming from agent mode)
     // Agent mode with --chat should start fresh without prompting
@@ -167,9 +169,15 @@ pub async fn run_interactive<W: UiWriter>(
         display_context_progress(&agent, &output);
 
         // Adjust prompt based on whether we're in multi-line mode
-        let prompt = if in_multiline { "... > " } else { "g3> " };
+        let prompt = if in_multiline {
+            "... > ".to_string()
+        } else if let Some(name) = agent_name {
+            format!("{}> ", name)
+        } else {
+            "g3> ".to_string()
+        };
 
-        let readline = rl.readline(prompt);
+        let readline = rl.readline(&prompt);
         match readline {
             Ok(line) => {
                 let trimmed = line.trim_end();

crates/g3-cli/src/lib.rs

@@ -218,7 +218,7 @@ async fn run_console_mode(
             combined_content,
             project.workspace(),
             cli.new_session,
-            false, // from_agent_mode
+            None, // agent_name (not in agent mode)
         )
         .await
     }