feat: add animated custom cursor with hover effects (#3022)

[hari2k7]

Description

Fixes #3022

Implemented a smooth animated custom cursor effect for enhanced user interaction.
The cursor consists of a sharp dot that follows the pointer instantly, and a
larger ring that lags behind with a lerp (smooth interpolation) effect.
On hover over interactive elements (buttons, links, cards, inputs), the ring
scales up and brightens to match the site's accent color (#58a6ff).
On mobile/touch devices, the default cursor is preserved via (pointer: fine) media query guard.

Pillar

• 🎨 Pillar 1 — New Theme Design
• 📐 Pillar 2 — Geometric SVG Improvement
• 🕐 Pillar 3 — Timezone Logic Optimization
• 🛠️ Other (Bug fix, refactoring, docs)

Visual Preview

CommitPulse._.3D.Isometric.GitHub.Contribution.Graph.-.Personal.-.Microsoft.Edge.2026-06-03.10-51-42.mp4

Checklist before requesting a review:

• I have read the CONTRIBUTING.md file.
• I have tested these changes locally (localhost:3000/api/streak?user=YOUR_USERNAME).
• I have run npm run format and npm run lint locally and resolved all errors.
• My commits follow the Conventional Commits format (e.g., feat(cursor): add animated cursor with hover effects).
• I have updated README.md if I added a new theme or URL parameter.
• I have started the repo.
• I have made sure that i have only one commit to merge in this PR.
• The SVG output matches the CommitPulse "premium quality" aesthetic standard.
• (Recommended) I joined the CommitPulse Discord community.

[github-actions]

👋 Hey @hari2k7, welcome to CommitPulse! 🎉

Thanks for opening your first pull request — this is a big deal and we appreciate the effort!

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