docs(skills): tracks-and-clips says image duration is optional, and a test pins the 3

Author: miguel-heygen

scripts/creator-editing-recipes.test.mjs

@@ -99,6 +99,7 @@ test("the add-media recipe uses Studio's default durations", async () => {
   assert.match(section, /`data-start` is enough/);
   assert.doesNotMatch(section, /ffprobe/);
   assert.match(section, /root composition's `data-duration` is at least/);
+  assert.match(section, new RegExp(`${imageSecs} for an image unless you set another`));
   assert.doesNotMatch(image, /data-duration/);
 });
 

skills-manifest.json

@@ -34,7 +34,7 @@
       "files": 11
     },
     "hyperframes-core": {
-      "hash": "cea1f2632dd66290",
+      "hash": "99a07539f407ca0d",
       "files": 11
     },
     "hyperframes-creative": {

skills/hyperframes-core/references/tracks-and-clips.md

@@ -10,7 +10,7 @@ A clip is any DOM element with `data-start` and, where required, `data-duration`
 - **Sub-composition hosts** — `<div>` with `data-composition-src`. Always require `data-duration`.
 - **Video clips** — `<video>` with `muted` and `playsinline`. Duration can default to media length.
 - **Audio clips** — `<audio>`. Duration can default to media length.
-- **Image clips** — `<img>`. Always require `data-duration`.
+- **Image clips** — `<img>`. `data-duration` is optional and defaults to 3 seconds; write it only for another length.
 
 Add `class="clip"` to authored visual clips. The runtime does not read it, but the scaffold's shared `.clip { position: absolute; inset: 0 }` rule is what gives a scene its full-frame box, Studio treats it as an edit hint, and `lint` warns without it.