Replace all hardcoded 'kindred-rd' schema references with the new
configurable get_schema_name() setting. Priority: FreeCAD preference
SchemaName > SILO_SCHEMA env var > default 'kindred-rd'.
- Add get_schema_name() to FreeCADSiloSettings and _get_schema_name() helper
- Add Schema Name field to Settings dialog
- Replace raw urllib calls in schema_form.py with SiloClient methods
(get_property_schema, generate_part_number)
- Inline parse_part_number/sanitize_filename (removed from silo-client)
- Simplify category folder naming to use category code directly
- Update silo-client submodule to origin/main + configurable schema branch
Closes#28
