fix: drop the show_preview ask-first override from two challenges

challenges/birdsbirdbirds/skills/start-challenge/SKILL.md

@@ -38,9 +38,8 @@ only because someone asks: its condition must hold.
 
 Open the drawing page right away, as your first action once the challenge
 starts (after `session_info`, when you have it): call `show_preview` with
-`http://127.0.0.1:4322/` without asking first. This challenge overrides the
-station's ask-first rule for `show_preview`, because the page is the
-challenge. Without `show_preview`, give them that URL to open right away.
+`http://127.0.0.1:4322/` without asking first. Without `show_preview`, give
+them that URL to open right away.
 
 When you resume with `draw-bird` not yet complete, first use `bash` to check
 whether `bird.png` exists in the current directory: a save made just before

challenges/vibe-coding-mad-libs/skills/start-challenge/SKILL.md

@@ -35,9 +35,7 @@ participant which step they finished instead, without mentioning points.
    you start building. A bracketed blank or a request to skip doesn't count.
 2. **build-app.** Write the app to `index.html`, then read it back to check
    it is whole. As soon as it is, call `show_preview` with
-   `http://127.0.0.1:4321/` without asking first. This challenge overrides the
-   station's ask-first rule for `show_preview`, because seeing the app is the
-   challenge.
+   `http://127.0.0.1:4321/` without asking first.
    When `show_preview` is missing or fails, give them that URL to open.
    Nothing watches the page, so ask them to try it and tell you how it went.
    Report `build-app` only after they say it works; if it doesn't, fix it and