Add profile page UI

[AlexMeng0831]

Summary

• add a new /profile page based on the Figma design
• implement the profile hero card, contact section, and lab affiliation section
• keep the page isolated from the earlier backend PR

Notes

• this version uses placeholder profile data for now
• backend wiring can be added in a follow-up if needed

Checklist before requesting a review

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• This change requires a documentation update

[AlexMeng0831]

The two screenshots

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