feat(onboard): pass CLI args as initial config to interactive wizard

--workspace and --config now work as initial defaults in interactive mode:
- The wizard starts with these values pre-filled
- Users can view and modify them in the wizard
- Final saved config reflects user's choices

This makes the CLI args more useful for interactive sessions while
still allowing full customization through the wizard.

nanobot/cli/commands.py

@@ -308,9 +308,8 @@ def onboard(
         from nanobot.cli.onboard_wizard import run_onboard
 
         try:
-            config = run_onboard()
-            # Re-apply workspace override after wizard
-            config = _apply_workspace_override(config)
+            # Pass the config with workspace override applied as initial config
+            config = run_onboard(initial_config=config)
             save_config(config, config_path)
             console.print(f"[green]✓[/green] Config saved at {config_path}")
         except Exception as e:

nanobot/cli/onboard_wizard.py

@@ -938,10 +938,17 @@ def _show_summary(config: Config) -> None:
 # --- Main Entry Point ---
 
 
-def run_onboard() -> Config:
-    """Run the interactive onboarding questionnaire."""
-    config_path = get_config_path()
+def run_onboard(initial_config: Config | None = None) -> Config:
+    """Run the interactive onboarding questionnaire.
 
+    Args:
+        initial_config: Optional pre-loaded config to use as starting point.
+                       If None, loads from config file or creates new default.
+    """
+    if initial_config is not None:
+        config = initial_config
+    else:
+        config_path = get_config_path()
         if config_path.exists():
             config = load_config()
         else: