Make csa-card-hover cards clickable via stretched csa-go link

[apannetrat]

Summary

• Adds position: relative to .csa-card-hover to establish the stacking context
• Adds a ::after pseudo-element on .csa-card-hover .csa-go stretched to inset: 0, making the entire card surface trigger the link on click
• No JS required — pure CSS stretched-link pattern (same technique as Bootstrap's stretched-link)

Caveat

Any other interactive element (second link, button) placed inside a hover card will need position: relative; z-index: 1 to sit above the overlay and remain independently clickable.

Test plan

• Click on card body (not the link text) — should follow the csa-go href
• Click directly on the csa-go link text — should still work normally
• Right-click on the card — browser context menu should offer "Open link in new tab"
• Verify hover lift animation still works
• Check on dark/black surfaces

[apannetrat]

@lumpster-csa I'd like your approval before merging this. I noticed that cards with the .csa-card-hover style containing a link are not clickable (except on the link itself) despite the cursor change. It felt wrong so I tried to fix this.

[lumpster-csa]

@apannetrat good catch and makes perfect sense to me for the entire card to be clickable.