🎨 Palette: [UX improvement] Add context-aware tooltips to VS Code extension error states

[raccioly]

💡 What:
Added specific icons ($(warning) and $(error)), background theme colors (warningBackground and errorBackground), and dynamic tooltips to the VS Code status bar item when the CDD output fails to parse or when the underlying refresh command throws an exception.

🎯 Why:
Previously, the extension showed a generic $(shield) CDD: ? state when the CLI command completely failed or when the JSON output could not be parsed. This hidden failure state offered no clues to the user regarding the underlying problem. By making the status bar informative, developers immediately know what went wrong (e.g., an error parsing output or an exception thrown), preventing confusion and aiding in faster troubleshooting.

📸 Before/After:
Before: $(shield) CDD: ? with tooltip "Click to see CDD score details" regardless of whether the output was unparseable or errored out.
After:

• Unparseable: $(warning) CDD: ? with yellow background and tooltip "Score unavailable - could not parse output."
• Exception: $(error) CDD: Error with red background and tooltip "Error refreshing score: [e.message]."

♿ Accessibility:
Providing descriptive error messages via tooltips, along with distinct visual and icon changes, helps convey semantic meaning and context changes to screen readers and users navigating via keyboard, making the extension more accessible and transparent.

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PR created automatically by Jules for task 18254233441658972471 started by @raccioly

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