Migrate structure allocations from calloc to glibs g_new0 macro to
improve type safety and memory robustness.
* Type Safety: The macro takes the type name directly, ensuring the
allocated size always matches the pointer type.
* Static Analysis: It guarantees a non-NULL return by aborting on
failure, which silences -fanalyzer warnings regarding potential NULL
pointer dereferences.
* Readability: Removes redundant sizeof() calls and is the glib way