feat: unit descriptions with tooltip action and admin textarea

src/lib/actions/tooltip.ts

@@ -0,0 +1,40 @@
+/**
+ * Svelte action: show a native `title` tooltip after a 500ms hover delay.
+ * If text is empty, does nothing.
+ */
+export function tooltip(node: HTMLElement, text: string) {
+  let timer: ReturnType<typeof setTimeout> | null = null;
+
+  function enter() {
+    if (!text) return;
+    timer = setTimeout(() => {
+      node.title = text;
+    }, 500);
+  }
+
+  function leave() {
+    if (timer !== null) {
+      clearTimeout(timer);
+      timer = null;
+    }
+    node.removeAttribute('title');
+  }
+
+  node.addEventListener('mouseenter', enter);
+  node.addEventListener('mouseleave', leave);
+
+  return {
+    update(newText: string) {
+      text = newText;
+      // If title is currently set, update it immediately
+      if (node.title) {
+        node.title = newText || '';
+      }
+    },
+    destroy() {
+      if (timer !== null) clearTimeout(timer);
+      node.removeEventListener('mouseenter', enter);
+      node.removeEventListener('mouseleave', leave);
+    }
+  };
+}