feat: add Copy Link, Twitter/X and LinkedIn share buttons to dashboar…

[111-Vaishali]

What does this PR do?

Adds three sharing buttons to the Dashboard header so users
can share their DevTrack stats with their network in one click.

Changes made

• Copy Link — copies the user's public profile URL to
  clipboard with a "✓ Copied!" confirmation for 2 seconds
  (reuses the existing handleCopyLink logic that was already
  written but never connected to any UI button)

• Post on X (Twitter) — opens Twitter with a pre-filled
  tweet containing the user's profile link and hashtags

• Share on LinkedIn — opens LinkedIn share dialog with
  the user's public profile URL

• Both desktop header and mobile dropdown menu updated

File changed

• src/components/DashboardHeader.tsx

Screenshots

[screenshot of the 3 buttons visible in dashboard header]

Related Issue

Closes #2265

[github-actions]

GSSoC Label Checklist 🏷️

@Umbrella-io — 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

[111-Vaishali]

Hi @Priyanshu-byte-coder, I've submitted a PR for this issue.
PR: #2265

[Priyanshu-byte-coder]

This PR has merge conflicts with the current main branch. Please rebase or merge main into your branch to resolve the conflicts, then push the updated branch. Once conflicts are resolved, this PR will be merged.

git fetch origin main
git merge origin/main
# resolve conflicts
git push