tests: major coverage round for node/render/audio/plugin subsystems
Add 12 gtest files (~400 tests) covering previously untested or
under-tested areas:
- node_math_test: MathNode operations across number/rational/vector/
matrix/color/sample pairings, shader code generation
- node_undo_test: all nodeundo command classes redo/undo
- track_test: Track block management, lookup, references, Value()
- render_diskcache_test: FrameHashCache EXR/JPEG round trips,
DiskManager LRU eviction, state persistence
- node_group_test: NodeGroup passthrough registration and serialization
- plugin_paraminstance_test: OFX param instances and clip image logic
- audio_waveform_test: AudioVisualWaveform + AudioProcessor
- node_value_extended_test: NodeValue conversions, NodeValueTable ops,
NodeKeyframe/bezier behavior
- render_projectcopier_test: ProjectCopier sync, PlaybackCache,
AudioPlaybackCache PCM segments
- node_core_test: Node input arrays, flags, contexts, links, keyframe
events, CopyInputs
- clip_traverser_test: ClipBlock speed/reverse/loop time mapping,
traverser time propagation
- audio_manager_viewer_test: AudioManager device API, ViewerOutput
params/streams/signals
Also fixes two real bugs found by the new tests:
- MathNode vec-vec divide crashed (debug) or produced NaN (release) on
the zero padding components of vec2/vec3 operands
- NodeKeyframe's default constructor left previous_/next_ and the
bezier handles uninitialized
Mike-Solar
576a843e4d