Remove automatic session resume suggestion on startup

- Remove the interactive prompt that asked users to resume in-progress sessions
- Remove unused new_session parameter from run_interactive()
- Remove unused info_inline() function from G3Status
- Explicit --resume <session_id> flag still works

crates/g3-cli/src/agent_mode.rs

@@ -292,7 +292,6 @@ pub async fn run_agent_mode(
             false, // show_code
             combined_content,
             &workspace_dir,
-            flags.new_session,
             Some(agent_name),  // agent name for prompt (e.g., "butler>")
             initial_project,
         )