feat: Add Credits & Attribution page

- add credits.njk
- add credits.css
- add tooltips.js
- add link in footer

src/scripts/tooltips.js

@@ -0,0 +1,47 @@
+// JS for tooltip hover
+document.addEventListener("DOMContentLoaded", () => {
+    // Hide inline thumbs when JS is available
+    document.querySelectorAll(".thumb-inline").forEach(img => img.style.display = "none");
+
+    // Tooltip element
+    const tip = document.createElement("div");
+    tip.className = "thumb-tooltip";
+    document.body.appendChild(tip);
+
+    function positionTip(el) {
+        const rect = el.getBoundingClientRect();
+        const tipRect = tip.getBoundingClientRect();
+        let left = rect.left + window.scrollX;
+        if (left + tipRect.width > window.innerWidth) {
+            left = window.innerWidth - tipRect.width - 8; // small margin
+        }
+        tip.style.top = (rect.bottom + window.scrollY + 6) + "px";
+        tip.style.left = left + "px";
+    }
+
+
+    function show(e) {
+        const url = e.currentTarget.getAttribute("data-tooltip");
+        if (!url) return;
+
+        // Preload image to get natural size
+        const img = new Image();
+        img.onload = () => {
+        tip.style.width = img.naturalWidth + "px";
+        tip.style.height = img.naturalHeight + "px";
+        tip.style.backgroundImage = `url("${url}")`;
+        tip.style.display = "block";
+        positionTip(e.currentTarget);
+        };
+        img.src = url;
+    }
+
+    function hide() { tip.style.display = "none"; }
+
+    document.querySelectorAll("li.credit").forEach(item => {
+        item.addEventListener("mouseenter", show);
+        item.addEventListener("mouseleave", hide);
+        item.addEventListener("focusin", show);
+        item.addEventListener("focusout", hide);
+    });
+});