fix(cli): align video output boundaries (#2490)

* fix(cli): align video output boundaries

* test(cli): honor CI ffmpeg fixture path

* test(cli): decouple duration precedence from ffmpeg

* test(cli): pin half-open video boundaries

* test(producer): refresh style 7 boundary golden

packages/core/src/runtime/init.test.ts

@@ -325,6 +325,33 @@ describe("initSandboxRuntimeModular", () => {
     expect(child.style.visibility).toBe("hidden");
   });
 
+  it("uses a half-open interval around a timed element's end boundary", () => {
+    const root = document.createElement("div");
+    root.setAttribute("data-composition-id", "main");
+    root.setAttribute("data-root", "true");
+    root.setAttribute("data-start", "0");
+    root.setAttribute("data-width", "1920");
+    root.setAttribute("data-height", "1080");
+    document.body.appendChild(root);
+
+    const clip = document.createElement("div");
+    clip.setAttribute("data-start", "0");
+    clip.setAttribute("data-duration", "2.5");
+    root.appendChild(clip);
+
+    window.__timelines = { main: createMockTimeline(5) };
+    initSandboxRuntimeModular();
+
+    window.__player?.renderSeek(2.5 - 1e-9);
+    expect(clip.style.visibility).toBe("visible");
+
+    window.__player?.renderSeek(2.5);
+    expect(clip.style.visibility).toBe("hidden");
+
+    window.__player?.renderSeek(2.5 + 1e-9);
+    expect(clip.style.visibility).toBe("hidden");
+  });
+
   it("keeps external composition hosts visible through their authored duration", async () => {
     const root = document.createElement("div");
     root.setAttribute("data-composition-id", "main");

packages/core/src/runtime/init.ts

@@ -583,7 +583,7 @@ export function initSandboxRuntimeModular(): void {
     const computedEnd =
       duration != null && duration > 0 ? start + duration : Number.POSITIVE_INFINITY;
     return (
-      currentTime >= start && (Number.isFinite(computedEnd) ? currentTime <= computedEnd : true)
+      currentTime >= start && (Number.isFinite(computedEnd) ? currentTime < computedEnd : true)
     );
   };
 
@@ -2827,7 +2827,7 @@ export function initSandboxRuntimeModular(): void {
             const mediaStart =
               Number.parseFloat(rawEl.dataset.playbackStart ?? rawEl.dataset.mediaStart ?? "0") ||
               0;
-            if (Number.isFinite(start) && state.currentTime >= start && state.currentTime <= end) {
+            if (Number.isFinite(start) && state.currentTime >= start && state.currentTime < end) {
               if (!rawEl.paused) {
                 clock.attachAudioSource({ el: rawEl, compositionStart: start, mediaStart });
                 foundActive = true;

packages/core/src/runtime/media.test.ts

@@ -250,6 +250,28 @@ describe("syncRuntimeMedia", () => {
     expect(clip.el.play).toHaveBeenCalled();
   });
 
+  it("uses a half-open interval around a clip's end boundary", () => {
+    const clip = createMockClip({ start: 0, end: 2.5 });
+    Object.defineProperty(clip.el, "readyState", { value: 4, writable: true });
+
+    syncRuntimeMedia({
+      clips: [clip],
+      timeSeconds: 2.5 - 1e-9,
+      playing: true,
+      playbackRate: 1,
+    });
+    expect(clip.el.play).toHaveBeenCalledTimes(1);
+
+    syncRuntimeMedia({ clips: [clip], timeSeconds: 2.5, playing: true, playbackRate: 1 });
+    syncRuntimeMedia({
+      clips: [clip],
+      timeSeconds: 2.5 + 1e-9,
+      playing: true,
+      playbackRate: 1,
+    });
+    expect(clip.el.play).toHaveBeenCalledTimes(1);
+  });
+
   it("plays synchronously even when media is unbuffered (preserves user gesture)", () => {
     // Calling play() synchronously inside the user-gesture call chain lets the
     // browser queue playback until data buffers, while consuming the transient

packages/core/src/runtime/media.ts

@@ -173,7 +173,7 @@ export function syncRuntimeMedia(params: {
     // (el.ended resets to false when the user scrubs back, so seeks work.)
     const isActive =
       params.timeSeconds >= clip.start &&
-      params.timeSeconds <= clip.end &&
+      params.timeSeconds < clip.end &&
       relTime >= 0 &&
       (!el.ended || clip.loop);
     if (isActive) {