[FEATURE] Add colored badge for good-first-issue labels

[ascender1729]

Description

Highlight issues with 'good first issue' label using a distinctive colored badge.

Why Needed

• Makes beginner-friendly issues stand out
• Helps new contributors find suitable issues
• Visual differentiation improves scanning

Implementation Details

• Detect 'good first issue' or 'good-first-issue' label
• Show green/highlighted badge
• Position prominently on issue card
• Add tooltip explaining the badge

Files to Modify

• src/components/results/IssueCard.svelte

Code Example

{#if hasGoodFirstIssueLabel(issue.labels)}
  <span 
    class="bg-green-500 text-white px-2 py-1 rounded-full text-xs"
    title="Great for first-time contributors"
  >
    Good First Issue
  </span>
{/if}

Acceptance Criteria

• Badge appears for good-first-issue labeled issues
• Visually distinct from other labels
• Tooltip explains meaning
• Works with different label variations

Time Estimates

• With AI: 180 minutes
• Without AI: 1200 minutes