feat(ui): add reusable copy-to-clipboard component with success checkmark animation (#1937)

[Rohitdey45]

📌 Description

This PR resolves issue #1937 by introducing a reusable CopyButton component (src/components/ui/CopyButton.tsx) that provides consistent animated visual feedback across all copy actions in the application.

⚙️ Key Changes

• New Reusable Component: Created CopyButton featuring:
  • Smooth checkmark (Check) scale animation upon copy action.
  • Temporary "Copied!" visual badge state for 2.5 seconds.
  • Automatic toast notification using sonner.
  • Reliable fallback for legacy browser clipboard execution.
• Integrated Across UI:
  • src/components/CopyLinkButton.tsx
  • src/components/BadgeSection.tsx (README badge markdown copy block)
  • src/components/career-intelligence/ExportPanel.tsx (Full resume text copy)

🧪 Verification

• Verified icon state transition on click.
• Verified clipboard copy execution and toast feedback.
• Synced with upstream main (0 merge conflicts).

Closes #1937

[github-actions]

GSSoC Label Checklist 🏷️

@Priyanshu-byte-coder — please apply the appropriate labels before merging:

Difficulty (pick one):

• level:beginner — 20 pts
• level:intermediate — 35 pts
• level:advanced — 55 pts
• level:critical — 80 pts

Quality (optional):

• quality:clean — ×1.2 multiplier
• quality:exceptional — ×1.5 multiplier

Validation (required to score):

• gssoc:approved — counts for points
• gssoc:invalid / gssoc:spam / gssoc:ai-slop — does not score

Type labels (type:*) are auto-detected from files and title. Review and adjust if needed.
Points formula: (difficulty × quality_multiplier) + type_bonus