Add Announcement Banner at the Top of Visualizer

[SakshayMahna]

Description

Add a dismissible banner at the top of the LaunchMap visualizer to show announcements or updates. This helps us broadcast messages like new features, feedback links, or community updates.

Current Message to Display:

"💬 Join our Discord"

Design Suggestions

• Position: Top of the screen
• Style: Light background, rounded edges, subtle border, dismiss (❌) button
• Behavior
  • Appears only once unless dismissed
  • Dismiss stores a flag in localStorage to hide on next load

Tasks

1. Add a banner <div> in src/getWebviewHtml.ts HTML.
2. Style it in webview/styles/base.css
3. Make the banner dismissible via a close button (X)
4. Store dismissal using localStorage

[SakshayMahna]

Hi @TahaMjp,
Instead can you work on #25 . That is more impactful and a gradual progression to a higher difficulty one.