- Add support for # (stringify) and ## (concatenation) operators in macro replacement lists
- Implement scc_pp_expand_string_unsafe() to process operator tokens during macro expansion
- Add helper macros to identify blank, stringify, and concatenation tokens in replacement lists
- Include missing headers (ctype.h, string.h) for character handling functions
- Update object macro expansion to use new string expansion function instead of simple concatenation
- Improve whitespace handling in macro replacement parsing to prevent interference with operator processing
- Rename `scc_lex_parse_is_identifier_header` to `scc_lex_parse_is_identifier_prefix` for clarity and add a TODO comment
- Update lexer to use the renamed function for consistency
- Fix package and dependency names in `cbuild.toml` (`smcc_pprocesser` → `scc_pprocesser`, `smcc_lex_parser` → `lex_parser`)
- Introduce new macro system with header file `pp_macro.h` defining macro types, structures, and management functions
- Refactor preprocessor initialization and cleanup in `pprocessor.c` to use new macro table and stream handling
- Replace legacy `hashmap` with `scc_pp_macro_table_t` for macro storage
- Improve error handling and resource management in preprocessor lifecycle