feat: add skill proficiency levels

[shivambind269-ai]

Description

Adds skill proficiency levels to improve personalized project recommendations.

Changes

• Added Beginner, Intermediate, and Advanced skill proficiency levels.
• Stores proficiency for each selected skill.
• Displays proficiency alongside selected skills.
• Added backward-compatible handling for existing skill data.
• Updated recommendation scoring to give different weights based on skill proficiency.
• Advanced skills have a stronger recommendation influence than Beginner skills.

Testing

• Python syntax validation passed.

• git diff --check passed.

• Verified proficiency-based scoring:

  • Beginner score: 8.0
  • Advanced score: 11.0

• Existing upstream dataset validation issue related to missing tech_stack remains unrelated to this feature.

Closes #1288

[vercel]

@shivambind269-ai is attempting to deploy a commit to the komalsony234-1530's projects Team on Vercel.

A member of the Team first needs to authorize it.

[shivambind269-ai]

Hi @maintainers,

The implementation for #1288 is complete and the DevPath CI/build and CodeQL checks are passing.

The remaining Vercel check shows "Authorization required to deploy", which appears to be related to deployment permissions.

Could you please review the PR when available?

Thank you!

[komalharshita]

@shivambind269-ai kindly resolve the merge conflicts

[komalharshita]

Approved for merge! Thanks for your contribution to DevPath