Return COMMON_DIALOG_ERROR_ARG_NULL (0x80B8000D) from scePlayerSelectionDialogGetResult and scePlayerSelectionDialogParamInitialize when output memory cannot be written, rather than crashing with SIGSEGV in host space.
- Write parameter and result data safely via GuestCopyOut_nid_no_patch.
- Preserve caller errno across copy checks.
- Add regression coverage in GuestPlayerSelectionDialog.cpp for unwritable destinations.
- Document host-safety fallbacks in docs/dev/debt/libScePlayerSelectionDialog.md.
Implement scePlayerSelectionDialogGetStatus and scePlayerSelectionDialogClose in libScePlayerSelectionDialog, matching the common dialog lifecycle convention across player dialogs, and add unit test coverage in GuestPlayerSelectionDialog.