feat(core): rename string and stream functions for clarity

- Rename `cstring_push` to `cstring_append_ch` and `cstring_push_cstr` to `cstring_append_cstr` for consistent naming with new `cstring_append` function
- Update all callers in lexer and tests to use new function names
- Rename stream `destroy` method to `drop` for consistency with resource management conventions
- Fix potential overflow in string capacity calculation by adjusting growth logic

runtime/libcore/src/stream.c

@@ -68,8 +68,8 @@ static cbool mem_probe_stream_back(core_probe_stream_t *_stream) {
     return true;
 }
 
-static usize mem_probe_stream_read_buf(core_probe_stream_t *_stream, char *buffer,
-                                   usize count) {
+static usize mem_probe_stream_read_buf(core_probe_stream_t *_stream,
+                                       char *buffer, usize count) {
     Assert(_stream != null);
     core_mem_probe_stream_t *stream = (core_mem_probe_stream_t *)_stream;
 
@@ -164,7 +164,7 @@ core_probe_stream_t *core_mem_probe_stream_init(core_mem_probe_stream_t *stream,
     stream->stream.read_buf = mem_probe_stream_read_buf;
     stream->stream.reset = mem_probe_stream_reset;
     stream->stream.is_at_end = mem_probe_stream_is_at_end;
-    stream->stream.destroy = mem_probe_stream_destroy;
+    stream->stream.drop = mem_probe_stream_destroy;
 
     return (core_probe_stream_t *)stream;
 }