Collection of 3.10 beta fixes

[riccardobl]

1. add missing settings in new backends
2. fix fallback when hw shadows are not supported by the backend
3. fix issues with high-dpi and scaled framebuffers and post processing
4. fix native plugin signing

Note: merge without squash, since every commit is standalone and a different fix

[gemini-code-assist]

Code Review

This pull request introduces several enhancements and bug fixes related to rendering, camera management, and platform-specific configurations in jMonkeyEngine. Key changes include refactoring the FilterPostProcessor to use dedicated processing cameras instead of mutating the original scene camera, which improves multi-view and display scaling support. Additionally, it adds fallback logic to software shadow comparison when hardware comparison is unsupported, implements early configuration and FPS capping for iOS, and introduces comprehensive unit and screenshot tests to verify these changes. No review comments were provided, so there is no further feedback to address.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.