The "View Plan" button in the plan card was non-functional when:

The preview panel was manually collapsed by the user
Starting a new app session (preview panel is closed initially)
The button only changed the preview mode to "plan" but didn't open the
panel, making it invisible to users.

Root Cause
[isPreviewOpenAtom]was set to false when starting the app and only set
back to true after streaming completes. The "View Plan" button only
called [setPreviewMode("plan")] but didn't call
[setIsPreviewOpen(true)], leaving the panel closed.

Solution
Added [setIsPreviewOpen(true)] to the "View Plan" button's onClick
handler to ensure the preview panel opens when users click the button.


Testing
The fix can be verified by:

Generating a plan in the chat
Collapsing the preview panel (or having it closed on new app start)
Clicking the "View Plan" button
Confirm the panel opens and shows the plan view
<!-- devin-review-badge-begin -->

---

<a href="https://app.devin.ai/review/dyad-sh/dyad/pull/3073"
target="_blank">
  <picture>
<source media="(prefers-color-scheme: dark)"
srcset="https://static.devin.ai/assets/gh-open-in-devin-review-dark.svg?v=1">
<img
src="https://static.devin.ai/assets/gh-open-in-devin-review-light.svg?v=1"
alt="Open with Devin">
  </picture>
</a>
<!-- devin-review-badge-end -->

---------
Co-authored-by: Mohamed Aziz Mejri <mjrmohamedaziz@gmail.com>