content: update Julie Wechsler contact email

[chengjiahao1234]

Type of Change

• Content Update (team)

Summary

Update Julie Wechsler's contact email to her Concordia address.

Changes Made

• Update _data/phd_students.yml to use julie.wechsler@mail.concordia.ca.
• Preserve her photo, role, profile links, and position in the team list.
• No styling or unrelated content changes.

Testing Checklist

• Desktop (1920x1080)
• Tablet (768x1024)
• Mobile (375x667)
• Light theme
• Dark theme
• Verified the new mailto link and removal of the old email
• Team images load correctly
• No browser console errors or layout overflow
• Ran bundle exec jekyll serve successfully
• Passed YAML regression checks and git diff --check

Screenshots

Not attached; this changes the email target only.

Related Issues

None.

Additional Notes

Only Julie's email field changed. No documentation update is required.

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By submitting this PR, I confirm:

• I have tested these changes locally
• I have followed the code standards in DEVELOPMENT.md
• I have updated documentation if needed (not applicable)
• I am ready for this to be reviewed and merged