fix: Linux GPU fallback and HUD window show safety net

- Add Linux GPU config: use EGL (better Wayland compat), disable VAAPI
  video decoder/encoder (many distros ship broken drivers causing
  'vaInitialize failed' and preventing renderer from loading)
- Add ready-to-show fallback for HUD window: if did-finish-load never
  fires (GPU failure), show the window after 500ms via ready-to-show

Ref #261

electron/main.ts

@@ -68,6 +68,15 @@ function configureGpuAccelerationSwitches() {
 		app.commandLine.appendSwitch("use-angle", "d3d11");
 		return;
 	}
+
+	// Linux: prefer EGL over GLX for better Wayland compatibility.
+	// Disable VAAPI — many distros ship broken drivers that cause
+	// "vaInitialize failed" and prevent the renderer from loading.
+	if (process.platform === "linux") {
+		app.commandLine.appendSwitch("use-gl", "egl");
+		app.commandLine.appendSwitch("disable-features", "VaapiVideoDecoder,VaapiVideoEncoder");
+		return;
+	}
 }
 
 async function logSmokeExportGpuDiagnostics() {

electron/windows.ts

@@ -498,6 +498,17 @@ export function createHudOverlayWindow(): BrowserWindow {
 		}, 100);
 	});
 
+	// Safety net: on Linux the renderer may fail to fire did-finish-load
+	// (e.g. GPU/VAAPI errors). Show the window after ready-to-show as fallback.
+	win.once("ready-to-show", () => {
+		setTimeout(() => {
+			if (!win.isDestroyed() && !win.isVisible()) {
+				win.show();
+				win.moveTop();
+			}
+		}, 500);
+	});
+
 	hudOverlayWindow = win;
 
 	// Reset the user's saved HUD position when displays change so the bar