feat(ui): modernize DevTrack interface with light blue & white theme

[BekkamMallishwari]

Summary

This PR modernizes the DevTrack interface by implementing a clean, professional light blue and white theme to improve the overall user experience.

Changes Made

• Updated the global color palette to a modern light blue and white theme
• Improved navbar styling and alignment
• Enhanced dashboard sidebar appearance
• Refined cards, buttons, selects, and textareas
• Improved empty state and footer styling
• Updated theme configuration for consistent UI
• Enhanced overall layout consistency and responsiveness

Testing

• Verified the application builds successfully
• Tested navigation and UI responsiveness
• Confirmed consistent theme across updated components

Related Issue

Closes #924

[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

[BekkamMallishwari]

Hi @Priyanshu-byte-coder, I've completed the UI/UX enhancements for Issue #924. Could you please review this PR and let me know if any changes are needed? Thank you!