fix(core): remove 1800s hard cap on timeline duration that silently truncated long compositions (#1114)

The runtime had a maxTimelineDurationSeconds field defaulting to 1800
(30 minutes) that clamped the TransportClock duration. Any seek beyond
this cap was silently clamped, so GSAP tweens starting past ~1700s
never received their totalTime() call and stayed at their pre-tween
state (e.g. opacity:0).

The data-duration attribute is the authored source of truth. The loop-
inflation guard (timelineLooksLoopInflated) already handles the infinite
repeat:-1 case this cap was meant to protect against.

Closes #1107

packages/core/src/runtime/timeline.ts

@@ -176,7 +176,6 @@ function buildTimelineClipLabel(node: Element, kind: RuntimeTimelineClip["kind"]
 
 export function collectRuntimeTimelinePayload(params: {
   canonicalFps: number;
-  maxTimelineDurationSeconds: number;
 }): RuntimeTimelineMessage {
   const runtimeWindow = window as Window & {
     __timelines?: Record<string, RuntimeTimelineLike | undefined>;
@@ -347,10 +346,7 @@ export function collectRuntimeTimelinePayload(params: {
           mediaWindowDurationCandidate,
           compositionWindowDurationCandidate,
         ));
-  const rootCompositionDuration =
-    preferredRootDuration != null
-      ? Math.min(preferredRootDuration, params.maxTimelineDurationSeconds)
-      : null;
+  const rootCompositionDuration = preferredRootDuration ?? null;
   const rootCompositionEnd =
     rootCompositionDuration != null ? rootCompositionStart + rootCompositionDuration : null;
   const timelineWindowEnd =
@@ -666,13 +662,7 @@ export function collectRuntimeTimelinePayload(params: {
   // hide structural/background tracks from the timeline UI; if we collapse the
   // payload duration down to the last visible clip end, the controls jump even
   // though playback still runs for the full authored root duration.
-  const safeDuration = Math.max(
-    1,
-    Math.min(
-      Math.max(maxEnd || 1, rootCompositionDuration ?? 0),
-      params.maxTimelineDurationSeconds,
-    ),
-  );
+  const safeDuration = Math.max(1, maxEnd || 1, rootCompositionDuration ?? 0);
   const shouldEmitNonDeterministicInf = timelineLooksLoopInflated && attrDurationCandidate == null;
   const durationInFrames = shouldEmitNonDeterministicInf
     ? Number.POSITIVE_INFINITY