Expand gtest coverage across recently changed modules
Adds ~60 new unit tests covering the modules touched in recent bug-fix
passes and UI refactors:
- RenderTicket: result/finish-count semantics, empty watcher defaults,
ticket-reuse rejection
- Preferences tabs: behavior options migrated into General/Audio tabs,
translation context helper, audio-tab initialization
- NodeView: context management, 'Show in Parameter Editor' action wiring
- PreviewAutoCacher: construction, pause toggles, single-frame render
cancellation, force-cache range
- SeekableWidget/TimeBasedWidget: scroll, marker editing, context reset
- OCIOLutNode: empty/missing/unsupported LUT paths, string direction
values, file-switching regression coverage
- ProxyManager: working filename, disabled state, empty proxy fields
- Frame/VideoParams/AudioParams/Timecode/ExportFormat/ExportCodec:
additional edge-case and enumeration coverage
Also fixes the PreferencesAudioTab test crash by initializing
AudioManager in the offscreen test environment.
All tests pass: ctest --output-on-failure
Mike-Solar
b7ff687220
