test: add structural parity coverage between ProjectCard and its skel…

[amankoli09]

Closes #501

📌 Description

Adds structural layout parity testing between ProjectCard.tsx and ProjectCardSkeleton.tsx to prevent unexpected layout shifts when data loads.

🛠️ Changes Made

• Tests Added: Asserted that ProjectCard and its skeleton share the exact same outer container structural classes (w-full, padding, border, etc.) under both normal and edge-case (missing optional tags, long wrapping text) conditions.
• Skeleton Update: Added the missing w-full class to ProjectCardSkeleton for perfect structural parity with the real card.
• Documentation: Added a convention comment to ProjectCardSkeleton.tsx noting that changes to the layout shape must be kept in sync between both components.

✅ Acceptance Criteria Verified

• Skeleton and real card share the same outer structural shape, verified by test.
• No layout-shift-prone mismatch found and left unaddressed.
• Existing card rendering for populated data is unaffected.