feat(np-signaling): report connection unavailable offline

[R3Dzf]

What

Implement sceNpSessionSignalingGetConnectionStatus in AnyPS5's existing PSN-offline model:

• Return SCE_NP_SESSION_SIGNALING_ERROR_INVALID_ARGUMENT for a null status pointer.
• Return SCE_NP_SESSION_SIGNALING_ERROR_UNAVAILABLE when there is no active PSN signaling network.
• Leave caller output buffers and peer address/port unchanged on failure.
• Add regression coverage to the existing guest_offline_imports suite and record unverified PS5 error precedence in TechnicalDebt.md.

Duplicate review: An initially investigated sceNpCheckNpAvailability change was reverted because upstream PR boykopovar#1543 already covers it. The final diff does not include that duplicate functionality.

Tested

• Linux: actual fork source built guest_offline_imports_tests; CTest passed.
• Windows: actual fork source built guest_offline_imports_tests with WinLibs; CTest passed.
• Cross-platform fork CI: success.
• Full AnyPS5 build, live PSN, and PS5 hardware behavior were not tested.

Scope

This implements offline error handling, not online multiplayer or connection establishment. It removes one throwing export from the progress scanner; hardware-level error precedence remains unverified.

AI-assisted: yes. Opened as a draft in the user's fork; upstream PR intake is paused.

[github-actions]

Thank you for your interest in the project! We are sorry, but we cannot accept more PRs while we work through the existing backlog. This PR has been automatically closed and labeled "intake paused". This is not a judgment of the quality of your changes.

[github-actions]

Progress report (8b393b6 → a4e3867)

📈 System libraries: 84.72% (+0.03%, +1 implemented functions)

✅ 1 implemented

Library	Name
libSceNpSessionSignaling	sceNpSessionSignalingGetConnectionStatus