feat(export): prepare native GPU beta candidate

Add validated native CUDA/D3D11 timeline retime, pause-aware capture timing, webcam source-time sampling, edited-track audio duration padding, packaged helper updates, and focused tests for PR webadderallorg#410 tester branch.

Author: meiiie

electron-builder.json5

@@ -5,8 +5,9 @@
   "electronUpdaterCompatibility": ">=2.16",
   "asar": true,
   "asarUnpack": [
-    "node_modules/ffmpeg-static/**",
-    "node_modules/uiohook-napi/**",
+    "node_modules/ffmpeg-static/**",
+    "node_modules/ffprobe-static/**",
+    "node_modules/uiohook-napi/**",
     "electron/native/**"
   ],
   "productName": "Recordly",
@@ -16,13 +17,16 @@
   "directories": {
     "output": "release"
   },
-  "files": [
+  "files": [
     "dist",
     "dist-electron",
     "electron/native",
+    "!node_modules/ffprobe-static/bin/darwin/**",
+    "!node_modules/ffprobe-static/bin/linux/**",
+    "!node_modules/ffprobe-static/bin/win32/ia32/**",
     "!electron/native/**/build/**",
     "!*.png",
-    "!preview*.png",
+    "!preview*.png",
     "!*.md",
     "!README.md",
     "!CONTRIBUTING.md",

electron/electron-env.d.ts

@@ -151,6 +151,7 @@ interface RendererNativeStaticLayoutMetrics extends RendererFfmpegAudioMuxMetric
 interface RendererNativeStaticLayoutProgress {
 	sessionId?: string;
 	backend?: RendererNativeStaticLayoutChunkMetric["backend"];
+	stage?: "preparing" | "finalizing";
 	elapsedMs?: number;
 	averageFps?: number;
 	instantFps?: number;
@@ -347,6 +348,13 @@ interface Window {
 				aspectRatio: number;
 			}>;
 			zoomTelemetry?: Array<{ timeMs: number; scale: number; x: number; y: number }>;
+			timelineSegments?: Array<{
+				sourceStartMs: number;
+				sourceEndMs: number;
+				outputStartMs: number;
+				outputEndMs: number;
+				speed: number;
+			}>;
 			chunkDurationSec?: number;
 			experimentalWindowsGpuCompositor?: boolean;
 			audioOptions?: {
@@ -755,9 +763,7 @@ interface Window {
 		setHasUnsavedChanges: (hasChanges: boolean) => void;
 		onRequestSaveBeforeClose: (callback: () => Promise<boolean>) => () => void;
 		isNativeWindowsCaptureAvailable: () => Promise<{ available: boolean }>;
-		muxNativeWindowsRecording: (
-			pauseSegments?: Array<{ startMs: number; endMs: number }>,
-		) => Promise<{
+		muxNativeWindowsRecording: (expectedDurationMs?: number) => Promise<{
 			success: boolean;
 			path?: string;
 			message?: string;