refactor(status-line): remove padding config

The status line is now inlined in the footer's left section,
so horizontal padding is no longer applicable. Remove padding
from StatusLineConfig, settings schema, JSON schema, and docs.

packages/cli/src/config/settingsSchema.ts

@@ -434,9 +434,7 @@ const SETTINGS_SCHEMA = {
         label: 'Status Line',
         category: 'UI',
         requiresRestart: false,
-        default: undefined as
-          | { type: 'command'; command: string; padding?: number }
-          | undefined,
+        default: undefined as { type: 'command'; command: string } | undefined,
         description: 'Custom status line display configuration.',
         showInDialog: false,
       },