feat(text): add text_audit spell-check and dry-run replacement simulation

- Adds 	ext_audit operation under ocs_read, control bridge, and headless server
- Implements pairs / dry_run_pairs simulation returning diffs, coordinates, and unmatched queries
- Implements check_terms suspect matching and dictionary vocabulary verification
- Adds dry_run: true to 	ext_replace to preview modifications without mutating entities or pushing undo
- Supports bounds, layers, handles, and scope filtering
- Updates MCP tool definitions, schemas, and automation test suites

docs/automation/mcp_smoke.py

@@ -52,16 +52,18 @@ def legacy(server: Path) -> None:
     names = set(definitions)
     assert names == TOOLS, names
     execute_request = definitions["ocs_execute"]["inputSchema"]["properties"]["request"]
-    assert len(execute_request["oneOf"]) == 38
+    assert len(execute_request["oneOf"]) == 39
     op_enum = execute_request["properties"]["op"]["enum"]
     for shipped in ("entities_create", "entities_delete", "entities_transform",
                     "block_define", "block_delete", "file_identity", "xdata_set",
                     "view_focus", "wblock", "plot",
                     "entities_copy_to", "group_create", "selection_set_save",
                     "selection_set_load", "close", "sysvar", "layout_create",
-                    "page_setup_set"):
+                    "page_setup_set", "text_replace"):
         assert shipped in op_enum, shipped
     assert "xdata_get" in definitions["ocs_read"]["inputSchema"]["properties"]["op"]["enum"]
+    assert "text_search" in definitions["ocs_read"]["inputSchema"]["properties"]["op"]["enum"]
+    assert "text_audit" in definitions["ocs_read"]["inputSchema"]["properties"]["op"]["enum"]
     assert execute_request["properties"]["steps"]["maxItems"] == 64
     assert execute_request["properties"]["cmd"]["examples"][0] == "LINE 0,0 10,10"
     assert "set_properties" in execute_request["properties"]["op"]["enum"]