fix: bug-fix sweep across node, audio, render, plugin subsystems

Node core:
- MathNode/TrigonometryNode combo strings realigned with Operation enums
- mathbase scalar/vector operand pick no longer uses bitwise type checks
- NodeSetPositionAndDependenciesRecursively moves dependencies again
- RemoveAllKeyframes undo actually restores keyframes
- NodeGroup GetInputName null-deref guard, passthrough ids use input id
- NodeValueTable::Has is an exact type match; tag fallback only for
  empty tags; kStrCombo/kPushButton get data type names
- delete_all_keyframes no longer loops forever on unparented keyframes;
  keyframe-load failures propagate; rational interpolation falls back to
  double; OpacityEffect no longer leaks its internal MathNode

Audio/footage:
- AudioVisualWaveform: GetSummaryFromTime underflow OOB read, TrimIn
  prepend length bookkeeping, OverwriteSums source channel indexing
- PanNode inserts the pan value into the sample job (keyframed pan
  works); OutputParamsChanged is emitted on device change; PortAudio
  device indices are validated before Pa_GetDeviceInfo
- Footage: AdjustTimeByLoopMode no longer hangs/UBs on degenerate
  lengths, GetStreamIndex bounds-checked, CheckFootage clears stale
  state on missing files, failed probes are not cached,
  FootageDescription::Load requires its own root element

Render/track:
- ViewerOutput pushes the tagged samples value; TrackList disconnects
  the track-height lambda; GetTrackFromReference validity check
- RenderManager dummy backend: null-initialized threads, guarded
  decoder-cache/timer paths; Renderer::Destroy releases color cache
  shaders/textures; unknown dynamic backends no longer alias to oakgl
- SharedMemoryRegion POSIX attach validates segment size; ReadMessage
  skips blank lines instead of failing; GC counter clamped;
  IsRenderingCustomRange implemented; TimeOffsetNode gets a true
  inverse OutputTimeAdjustment; zero-speed clips return the held frame

Plugin/nodes:
- OliveClip: stored default region of definition is honored, on-demand
  images are cached; OliveHost sets host identity properties and logs
  instead of showing modal dialogs offscreen; Plugin.h dead decls gone
- DespillNode guards graph-less use with Rec.709 fallback; description
  typos fixed (despill, swirl); mosaic applies when only one axis
  matches; Windows-only Project filename separator test fixed

app/audio/audiovisualwaveform.cpp

@@ -168,8 +168,9 @@ void AudioVisualWaveform::OverwriteSums(const AudioVisualWaveform &sums,
 		size_t our_start_index =
 			time_to_samples(dest - virtual_start_, rate_dbl);
 
-		// Get our source sample
-		size_t their_start_index = time_to_samples(offset, rate_dbl);
+		// Get our source sample, indexing with the SOURCE's channel count
+		size_t their_start_index = std::floor(offset.toDouble() * rate_dbl) *
+								   sums.channel_count();
 		if (their_start_index >= their_arr.size()) {
 			continue;
 		}
@@ -260,7 +261,11 @@ void AudioVisualWaveform::TrimIn(rational length)
 		}
 	}
 
-	length_ = qMax(rational(0), length_ - length);
+	if (!negative) {
+		length_ = qMax(rational(0), length_ - length);
+	}
+	// Prepending grows the data before the existing start, so the absolute
+	// end (which length_ tracks) is unchanged
 }
 
 AudioVisualWaveform AudioVisualWaveform::Mid(const rational &offset) const
@@ -321,14 +326,16 @@ AudioVisualWaveform::GetSummaryFromTime(const rational &start,
 
 	const Sample &mipmap_data = using_mipmap->second;
 
-	// Determine if the array actually has this sample
-	sample_length = qMin(sample_length, mipmap_data.size() - start_sample);
+	// Determine if the array actually has this sample. Compare in signed
+	// arithmetic so a start past the end of the data doesn't underflow.
+	qint64 available = qint64(mipmap_data.size()) - qint64(start_sample);
+	if (available > 0) {
+		sample_length = qMin(sample_length, size_t(available));
 
-	// Based on the above `min`, if sample length <= 0, that means start_sample >= the size of the
-	// array and nothing can be returned.
-	if (sample_length > 0) {
-		return ReSumSamples(&mipmap_data.data()[start_sample], sample_length,
-							channels_);
+		if (sample_length > 0) {
+			return ReSumSamples(&mipmap_data.data()[start_sample],
+								sample_length, channels_);
+		}
 	}
 
 	// Return null samples