pipeline: finalize PipelineState migration

- Add public wrappers get_pipeline_state() and sync_module_state()
- Update TUI pipeline_runner to use public accessors and lazy- import CLI deps
- Update get_tag docstring to avoid referencing internal variables
- Update tests to use public API

cmdlet/get_tag.py

@@ -326,7 +326,7 @@ def _emit_tags_as_table(
     """Emit tags as TagItem objects and display via ResultTable.
 
     This replaces _print_tag_list to make tags pipe-able.
-    Stores the table in ctx._LAST_RESULT_TABLE for downstream @ selection.
+    Stores the table via ctx.set_last_result_table_overlay (or ctx.set_last_result_table) for downstream @ selection.
     """
     from SYS.result_table import ResultTable