feat: add PaletteBot - automated VSCode theme change monitor

[LiamM2004]

Summary

• Adds design-tokens/vscode_themes.json — the Figma variable collection for VSCode themes (2026 Light, 2026 Dark, HC Black) committed as the source of truth
• Adds scripts/check-vscode-themes.mjs — fetches upstream VSCode theme files from microsoft/vscode, diffs them against the stored JSON, and updates it in place. Changes are grouped by component, filtered for case-only differences, and output as Markdown
• Adds .github/workflows/vscode-theme-monitor.yml — PaletteBot workflow that runs on the 1st of every month, commits any changes, and posts a diff summary as a comment on a persistent tracking issue

How it works

PaletteBot runs monthly via GitHub Actions. If Microsoft changes any color tokens in the 2026 Light, 2026 Dark, or HC Black themes, PaletteBot:

1. Updates design-tokens/vscode_themes.json automatically
2. Posts a comment on the PaletteBot — VSCode Theme Changes tracking issue with changes grouped by component (e.g. button, editor, list) showing token name, old hex, and new hex

Designers can subscribe to the tracking issue to receive notifications. No secrets or external services required — uses the built-in GITHUB_TOKEN.

[hyperspace-pr-bot]

The pull request is too large to be processed by Feature Automatic Summary:
Pull request has 73279 lines changed, which exceeds the maximum of 50000 lines.

PR Bot Information

Version: 1.29.2

• Event Trigger: pull_request.opened
• Correlation ID: 7f3b4fe0-8682-11f1-9a25-c889d22cf336

[changeset-bot]

⚠️ No Changeset found

Latest commit: 40d0238

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud