feat(python): text and dimension styles (doc.text_styles, doc.dim_styles)

Extends TableOperation with text style create/modify, dimension style
create/modify (DimStyle fields as a validated JSON object), rename, delete and
set-current. Reuses OCS's style in-use scan and reference-following rename
(four style_ops methods widened to pub(super)); a renamed text style also
updates dimension styles that name it. Real-IPC audit with DWG/DXF persistence
and undo, IPC and Python unit tests, docs. Four cadcodec findings are pinned by
canaries.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/mod.rs

@@ -35,7 +35,7 @@ mod record_api;
 pub(crate) mod settings;
 mod shortcuts;
 mod startup;
-mod style_ops;
+pub(crate) mod style_ops;
 mod text_inline;
 mod tolerance_dialog;
 mod update;