docs: give every click-to-play video an audio track

Ten videos on the docs site played in silence. The player is click-to-play, so a
reader deliberately starts them and gets nothing — which reads as broken rather
than as a stylistic choice.

The music is from HeyGen's own catalogue, pulled through the media-use skill's
resolve path with the account already authenticated on this machine. That matters
more than convenience: the launch projects on disk carry a `launch-music-trimmed.mp3`
with no licence, no attribution and no metadata, and three Pixabay tracks. Neither
belongs on the official docs CDN, where objects cache immutably for a year.

Mixed at roughly -22 to -24 dB mean so it sits under the picture. Getting there
took two corrections worth recording: proportional fades, because a 1.2s fade-out
on a 5s clip eats half the audio; and seeking 11s into the bed, because its first
ten seconds are a quiet intro that dragged every short clip down to -27 dB.

The three Examples tiles are left silent on purpose — they are muted autoplay
loops, so an audio track would only be weight.

Verified: every video referenced anywhere under docs/ that is not a muted
autoplay tile now has an AAC stream, checked against the live CDN URL rather than
the local file.

docs/examples.mdx

@@ -32,7 +32,7 @@ Each preview links to the complete source project.
 >
   <video
     className="aspect-video w-full object-cover"
-    src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/website-to-hyperframes-preview.mp4"
+    src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/website-to-hyperframes-preview-v4.mp4"
     poster="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/website-to-hyperframes-poster.jpg"
     autoPlay
     muted

docs/guides/captions-and-recuts.mdx

@@ -12,7 +12,7 @@ description: "Add captions, add designed overlays, or change the spoken edit."
     playsInline
     preload="metadata"
     poster="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/wfv2-captions.jpg"
-    src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/wfv2-captions.mp4"
+    src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/wfv2-captions-v4.mp4"
   />
 </Frame>
 

docs/guides/faceless-explainer.mdx

@@ -9,7 +9,7 @@ Start from a topic, article, or notes. HyperFrames invents the typography, diagr
 <Frame caption="A short preview from a SpaceX valuation explainer. Every visual was invented from the question and numbers.">
   <video
     className="aspect-video w-full object-cover bg-zinc-100 dark:bg-zinc-900"
-    src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/wfv2-explainer.mp4"
+    src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/wfv2-explainer-v4.mp4"
     poster="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/wfv2-explainer.jpg"
     autoPlay
     muted

docs/guides/gsap-animation.mdx

@@ -11,7 +11,7 @@ GSAP is the primary animation runtime for HyperFrames compositions. You author t
 
 <DocsVideo
   title="GSAP keyframes on screen, and the ease curve being shaped in Studio"
-  src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/gsap-keyframes-demo-v1.mp4"
+  src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/gsap-keyframes-demo-v2.mp4"
   poster="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/gsap-keyframes-demo-v1.jpg"
 />
 

docs/guides/hdr.mdx

@@ -10,7 +10,7 @@ HyperFrames detects HDR media during render. When an MP4 project contains a BT.2
 
 <DocsVideo
   title="What HDR rendering produces, measured rather than simulated"
-  src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/hdr-render-demo-v1.mp4"
+  src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/hdr-render-demo-v2.mp4"
   poster="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/hdr-render-demo-v1.jpg"
 />
 

docs/guides/media-effects.mdx

@@ -14,7 +14,7 @@ Here is the whole range on real footage:
 
 <DocsVideo
   title="Every media effect family, applied to real sources"
-  src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/media-effects-showcase-v1.mp4"
+  src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/media-effects-showcase-v2.mp4"
   poster="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/media-effects-showcase-v2.jpg"
 />
 

docs/guides/remove-background.mdx

@@ -19,7 +19,7 @@ model locally; it does not upload the source or require an API key.
 
 <DocsVideo
   title="A presenter cut out of a real room, shown against the original and magnified at the hard edges"
-  src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/remove-background-demo-v1.mp4"
+  src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/remove-background-demo-v2.mp4"
   poster="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/remove-background-demo-v1.jpg"
 />
 

docs/guides/slideshow.mdx

@@ -9,7 +9,7 @@ A HyperFrames slideshow stays interactive. The result is a live, navigable deck
 <Frame caption="A real deck: points reveal, slides advance, a hotspot opens optional detail, then the presenter returns to the main story.">
   <video
     className="aspect-video w-full object-cover bg-zinc-100 dark:bg-zinc-900"
-    src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/wfv2-slideshow.mp4"
+    src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/wfv2-slideshow-v4.mp4"
     poster="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/wfv2-slideshow.jpg"
     autoPlay
     muted

docs/guides/video-components.mdx

@@ -15,7 +15,7 @@ behave the same in preview and the final render.
     playsInline
     preload="metadata"
     poster="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/studio-media-edit-loop-v1.jpg"
-    src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/studio-media-edit-loop-v1.mp4"
+    src="https://static.heygen.ai/hyperframes-oss/docs/images/showcase/studio-media-edit-loop-v4.mp4"
   />
 </Frame>
 

docs/snippets/advanced-path-grid.jsx

@@ -36,7 +36,7 @@ export const AdvancedPathGrid = () => {
         "Validate the project, render through Studio, an agent, or the CLI, and review the file.",
       action: "Finish the project",
       href: "/guides/export-and-share",
-      video: `${CDN}/studio-check-render-loop-v2.mp4`,
+      video: `${CDN}/studio-check-render-loop-v5.mp4`,
       poster: `${CDN}/studio-check-render-loop-v2.jpg`,
     },
   ];

docs/snippets/workflow-chooser.jsx

@@ -21,14 +21,14 @@ export const WorkflowChooser = () => {
       title: "Explain an idea",
       bring: "Bring notes, an article, a script, or one rough thought.",
       href: "/guides/faceless-explainer",
-      video: `${CDN}/wfv2-explainer.mp4`,
+      video: `${CDN}/wfv2-explainer-v4.mp4`,
       poster: `${CDN}/wfv2-explainer.jpg`,
     },
     {
       title: "Work with existing footage",
       bring: "Bring a talking-head, interview, or podcast clip.",
       href: "/guides/captions-and-recuts",
-      video: `${CDN}/wfv2-captions.mp4`,
+      video: `${CDN}/wfv2-captions-v4.mp4`,
       poster: `${CDN}/wfv2-captions.jpg`,
     },
     {
@@ -56,7 +56,7 @@ export const WorkflowChooser = () => {
       title: "Build a presentation",
       bring: "Bring an outline, pitch, report, or existing deck.",
       href: "/guides/slideshow",
-      video: "https://static.heygen.ai/hyperframes-oss/docs/images/showcase/wfv2-slideshow.mp4",
+      video: "https://static.heygen.ai/hyperframes-oss/docs/images/showcase/wfv2-slideshow-v4.mp4",
       poster: "https://static.heygen.ai/hyperframes-oss/docs/images/showcase/wfv2-slideshow.jpg",
     },
     {