PS_AI_Behavior: make spline StopFollowing a firm, BT-respected stop

StopFollowing() now sets a bManuallyStopped flag (cleared only by an explicit StartFollowing/StartFollowingAtDistance). The FindAndFollowSpline and FollowSpline BT tasks bail while it is set, so the BT no longer auto-resumes a manual stop on the next tick. ResumeFollowing() also respects the flag. PauseFollowing() is unchanged (BT may resume).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Unreal/PS_AI_Agent/Plugins/PS_AI_Behavior/Source/PS_AI_Behavior/Private/BT/PS_AI_Behavior_BTTask_FindAndFollowSpline.cpp

@@ -32,6 +32,14 @@ EBTNodeResult::Type UPS_AI_Behavior_BTTask_FindAndFollowSpline::ExecuteTask(
 		return EBTNodeResult::Failed;
 	}
 
+	// Respect a manual StopFollowing(): do not search for or resume a spline until
+	// the caller explicitly StartFollowing() again. Without this, the task would
+	// resume any CurrentSpline and override the stop on the very next tick.
+	if (Follower->bManuallyStopped)
+	{
+		return EBTNodeResult::Failed;
+	}
+
 	// Debug: log state on entry
 	if (UPS_AI_Behavior_Statics::IsDebugEnabled(AIC->GetPawn()))
 	{
@@ -268,6 +276,18 @@ void UPS_AI_Behavior_BTTask_FindAndFollowSpline::TickTask(
 		return;
 	}
 
+	// Manual StopFollowing() requested mid-approach: cancel the move-to-spline and bail.
+	if (UPS_AI_Behavior_SplineFollowerComponent* StopCheck =
+			AIC->GetPawn()->FindComponentByClass<UPS_AI_Behavior_SplineFollowerComponent>())
+	{
+		if (StopCheck->bManuallyStopped)
+		{
+			AIC->StopMovement();
+			FinishLatentTask(OwnerComp, EBTNodeResult::Failed);
+			return;
+		}
+	}
+
 	// Check if we've reached the spline
 	if (AIC->GetMoveStatus() == EPathFollowingStatus::Idle)
 	{

Unreal/PS_AI_Agent/Plugins/PS_AI_Behavior/Source/PS_AI_Behavior/Private/BT/PS_AI_Behavior_BTTask_FollowSpline.cpp

@@ -24,6 +24,12 @@ EBTNodeResult::Type UPS_AI_Behavior_BTTask_FollowSpline::ExecuteTask(
 		AIC->GetPawn()->FindComponentByClass<UPS_AI_Behavior_SplineFollowerComponent>();
 	if (!Follower) return EBTNodeResult::Failed;
 
+	// Respect a manual StopFollowing(): refuse to resume until an explicit restart.
+	if (Follower->bManuallyStopped)
+	{
+		return EBTNodeResult::Failed;
+	}
+
 	if (!Follower->CurrentSpline)
 	{
 		UE_LOG(LogPS_AI_Behavior, Warning, TEXT("[%s] FollowSpline: no current spline set."),

Unreal/PS_AI_Agent/Plugins/PS_AI_Behavior/Source/PS_AI_Behavior/Private/PS_AI_Behavior_SplineFollowerComponent.cpp

@@ -58,6 +58,7 @@ bool UPS_AI_Behavior_SplineFollowerComponent::StartFollowingAtDistance(
 	CurrentDistance = FMath::Clamp(StartDistance, 0.0f, Spline->GetSplineLength());
 	bMovingForward = bForward;
 	bIsFollowing = true;
+	bManuallyStopped = false; // an explicit Start lifts any previous manual stop
 	LastHandledJunctionIndex = -1;
 
 	UE_LOG(LogPS_AI_Behavior, Warning,
@@ -82,18 +83,23 @@ bool UPS_AI_Behavior_SplineFollowerComponent::StartFollowingAtDistance(
 void UPS_AI_Behavior_SplineFollowerComponent::StopFollowing()
 {
 	bIsFollowing = false;
-	UE_LOG(LogPS_AI_Behavior, Verbose, TEXT("[%s] Stopped following spline."),
+	// Firm, manual stop: the Behavior Tree spline tasks will refuse to re-start
+	// following until StartFollowing()/StartFollowingAtDistance() is called again.
+	bManuallyStopped = true;
+	UE_LOG(LogPS_AI_Behavior, Log, TEXT("[%s] StopFollowing: manual stop (BT will not auto-resume)."),
 		GetOwner() ? *GetOwner()->GetName() : TEXT("?"));
 }
 
 void UPS_AI_Behavior_SplineFollowerComponent::PauseFollowing()
 {
+	// Pause is NOT a manual stop — the BT is allowed to resume it.
 	bIsFollowing = false;
 }
 
 void UPS_AI_Behavior_SplineFollowerComponent::ResumeFollowing()
 {
-	if (CurrentSpline)
+	// Do not resume over a manual stop — only an explicit Start lifts that.
+	if (CurrentSpline && !bManuallyStopped)
 	{
 		bIsFollowing = true;
 	}

Unreal/PS_AI_Agent/Plugins/PS_AI_Behavior/Source/PS_AI_Behavior/Public/PS_AI_Behavior_SplineFollowerComponent.h

@@ -106,6 +106,13 @@ public:
 	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Replicated, Category = "Spline Follower|Runtime")
 	bool bIsFollowing = false;
 
+	/** Set by StopFollowing(): a firm, manual stop. While true, the Behavior Tree
+	 *  spline tasks refuse to (re)start following — only an explicit StartFollowing()
+	 *  / StartFollowingAtDistance() clears it. This is what distinguishes a deliberate
+	 *  stop from PauseFollowing() (which the BT is allowed to auto-resume). */
+	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = "Spline Follower|Runtime")
+	bool bManuallyStopped = false;
+
 	// ─── Delegates ──────────────────────────────────────────────────────
 
 	/** Fired when approaching a junction. Use to make custom spline selection. */