Fix VS Code informational message not disappearing after aspire add

[Copilot]

Problem

When running aspire add command in VS Code, the informational success message would remain visible indefinitely after the operation completed, rather than automatically dismissing like other messages.

Root Cause

The issue occurred due to a timing mismatch between progress notification clearing and success message display:

1. AddCommand uses ShowStatusAsync to display a progress notification during package installation
2. When the operation completes, ShowStatusAsync sends null to clear the progress notification
3. The ProgressNotifier has a 250ms debounce delay before actually clearing (to handle rapid status updates)
4. AddCommand immediately calls DisplaySuccess to show the success message
5. DisplaySuccess displayed a new information modal but didn't clear the pending progress notification
6. After 250ms, the progress notification would disappear, leaving the success modal visible

Solution

Updated displaySuccess, displayMessage, and displayPlainText methods in the extension's InteractionService to call clearProgressNotification() after displaying their messages. This ensures any pending progress notifications are immediately cleared, matching the existing behavior of displayError.

Changes

extension/src/server/interactionService.ts

• Added clearProgressNotification() call to displaySuccess()
• Added clearProgressNotification() call to displayMessage()
• Added clearProgressNotification() call to displayPlainText()

extension/src/test/rpc/interactionServiceTests.test.ts

• Added test: "displaySuccess clears progress notification"
• Added test: "displayMessage clears progress notification"
• Added test: "displayPlainText clears progress notification"

Testing

• All existing tests pass
• New tests verify progress notifications are properly cleared
• Linting and compilation successful
• Changes are consistent with existing displayError implementation

Fixes: Issue where VS Code informational message does not go away after aspire add

Original prompt

---

This section details on the original issue you should resolve

<issue_title>VS Code informational message does not go away after aspire add</issue_title>
<issue_description></issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #12224

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.