fix(styles): reload Table/MLine buffers on structural ops, validate cell text style

style_new/copy/delete funneled through a load_style_bufs no-op for Table/MLine, leaving stale editor buffers pointed at the fresh style; both arms now route to the existing loaders. Table cell text-style typos persisted as dangling names; unknown names are now rejected with command-line feedback, keeping the buffer text for correction. Silent numeric parse-drops deliberately untouched (codebase-wide keep-old-valid norm). Tests: table_new_reloads_cell_buffers plus table_cell_unknown_text_style_is_rejected incl. retention assert (RED each verified by temporary revert). Full suite: 2048 passed / 0 failed / 25 ignored, zero warnings.

src/app/style_ops.rs

@@ -309,7 +309,8 @@ impl OpenCADStudio {
             StyleKind::Text => self.load_textstyle_bufs(i),
             StyleKind::Dim => self.load_dimstyle_bufs(i),
             StyleKind::MLeader => self.load_mleaderstyle_bufs(i),
-            StyleKind::Table | StyleKind::MLine => {}
+            StyleKind::Table => self.load_tablestyle_bufs(i),
+            StyleKind::MLine => self.load_mlstyle_bufs(i),
         }
     }