fix(ci): Fix AppImage build failures for OCR and HardSubX variants

OCR build fix:
- linuxdeploy was failing with "Invalid magic bytes in file header"
  because it was passed the wrapper script instead of the actual binary
- When OCR is enabled, ccextractor is renamed to ccextractor.bin and
  a wrapper script sets TESSDATA_PREFIX before executing the binary
- Now correctly passes ccextractor.bin to linuxdeploy when it exists

HardSubX build fix:
- Add libavdevice-dev to FFmpeg dependencies in CI workflow
- rusty_ffmpeg requires libavdevice which was missing

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/workflows/build_appimage.yml

@@ -83,7 +83,8 @@ jobs:
             libavutil-dev \
             libswscale-dev \
             libswresample-dev \
-            libavfilter-dev
+            libavfilter-dev \
+            libavdevice-dev
 
       - name: Install Rust toolchain
         if: steps.should_build.outputs.should_build == 'true'