safe LMB hold-to-skip cutscenes and multiple images with crossfade

src/dialogue/DialogueRuntime.h

@@ -27,6 +27,8 @@ public:
 	void confirmAdvance();
 	void moveSelection(int delta);
 	void selectChoice(int index);
+	bool canSkipCurrentCutscene() const;
+	void skipCurrentCutscene();
 
 	const PresentationModel& getPresentation() const { return presentation; }
 
@@ -58,7 +60,7 @@ private:
 	PresentationModel presentation;
 	Mode mode = Mode::Inactive;
 
-	int selectedChoice = 0;
+	int selectedChoice = -1;
 	float revealCharacters = 0.0f;
 	float revealSpeedCharsPerSecond = 52.0f;
 	
@@ -77,10 +79,12 @@ private:
 	void presentChoices(const Node& node);
 	void startCutscene(const std::string& cutsceneId, const std::string& nextNodeAfterCutscene);
 	void finishCutscene();
+	void syncCutsceneLineToElapsedTime();
 
 	void advanceCutsceneLine();
 	void refreshCutscenePresentation();
 	CutsceneCameraBlendState evaluateCutsceneCameraBlend() const;
+	std::vector<PresentedCutsceneImage> evaluateCutsceneImages() const;
 
 	static float applyEasing(EasingType easing, float t);
 	static int computeFallbackCutsceneDurationMs(const std::string& text);