feat: add icons for cuelang

[tsvl]

Description

Added icons for cuelang .cue files and cue/cues folders. Note: the official cuelang colors are very dark blues ( #232a68, #1b3987, #063AC0) which are difficult to represent here - I've tried to find a compromise that's consistent with existing icons and doesn't require separate light/dark variants, but there may be a better way to do it.

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[Copilot]

Pull Request Overview

This PR adds icon support for CueLang by introducing icons for .cue file extensions and cue/cues folder names. The contributor notes they've chosen Material Design colors as a compromise since the official CueLang colors are very dark blues that would be difficult to represent without separate light/dark variants.

Key Changes

• Added CueLang language icon configuration
• Added folder icon mappings for cue and cues directories
• Added file icon mapping for .cue file extensions

Reviewed Changes

Copilot reviewed 3 out of 6 changed files in this pull request and generated no comments.

File	Description
src/core/icons/languageIcons.ts	Registers the 'cue' language icon
src/core/icons/folderIcons.ts	Adds folder icon mappings for 'cue' and 'cues' folder names
src/core/icons/fileIcons.ts	Adds file icon mapping for '.cue' file extensions

[github-actions]

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[lucas-labs]

Thanks for your PR!
LGTM!

[github-actions]

Merge Successful

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