Linux support (#381)

* Add desktop release CI and support for Arch Linux packaging

* Make Gradle wrapper executable in desktop-release workflow

* Make Gradle wrapper executable in desktop-release workflow

* Make Gradle wrapper executable in desktop-release workflow

* Configure Gradle and update Java environment in desktop-release workflow

* Update Java setup and AUR packaging in desktop release workflow

* Update Java setup and AUR packaging in desktop release workflow

* Add MSIX packaging support for Windows desktop distribution

* Update AUR packaging metadata and validation

* Use spine toc attribute for NCX resolution

* crash fixes

* Implement automatic discovery and injection of EPUB font face siblings

* Enhance custom font support with family grouping and variable font handling

* Optimize metadata loading and improve TTS highlighting

* Add keyboard navigation support for EPUB reader

* Refine PDF spread page sizing to respect aspect ratios

* Implement responsive maximum height for reader popups and sheets

* Handle TTS generation failures by skipping problematic chunks

* Refactor PDF tile rendering logic and zoom indicator behavior

* Prefer block and offset locators over page index in native vertical flow

* Implement save and share actions for original book files

* Add Estonian language support

* Implement temporary viewing mode for external files

* Implement direct opening for temporary external files without library persistence

* fix failing tests

* Import SharedFileCapabilities in DesktopLibraryUi

* Improve native vertical reader progress, persistence, and image support

* Center target in viewport for native vertical reader and support animated scrolling

.gitignore

@@ -24,4 +24,6 @@ third_party/pdfium/
 cache/
 worker/
 output/
-policies/
+policies/
+episteme-bin/
+episteme-oss-bin/