feat(client): add create/edit environment pages and hoverable cards

- add CreateEnvironmentPage and EditEnvironmentPage with pre-filled form
- add /environments/new and /environments/:id/edit routes
- add Edit option to card context menu and detail page toolbar
- move env id pill to card footer (left), timestamp stays right
- make env cards clickable (navigate to detail); cog stops propagation
- add hoverable Card variant with primary border+shadow on hover
- add link color tokens and global anchor styles for both themes
- fix Timestamp pill visibility in dark mode with border token
- add DescriptionList truncate prop with ellipsis and title tooltip
- stack DescriptionList dd below dt with 8px gap between items

client/src/ui/Card/Card.module.css

@@ -47,3 +47,12 @@
 .sm { padding: var(--space-3) var(--space-4); }
 .md { padding: var(--space-4) var(--space-6); }
 .lg { padding: var(--space-6) var(--space-8); }
+
+.hoverable {
+  cursor: pointer;
+  transition: border-color var(--transition), box-shadow var(--transition);
+}
+.hoverable:hover {
+  border-color: var(--color-primary);
+  box-shadow: var(--shadow-sm), 0 0 0 1px var(--color-primary);
+}

client/src/ui/Card/Card.tsx

@@ -8,6 +8,7 @@ export interface CardProps {
   header?: React.ReactNode;
   headerVariant?: 'primary' | 'secondary';
   footer?: React.ReactNode;
+  onClick?: React.MouseEventHandler<HTMLDivElement>;
 }
 
 export function Card({
@@ -17,10 +18,17 @@ export function Card({
   header,
   headerVariant = 'primary',
   footer,
+  onClick,
 }: CardProps) {
   return (
     <div
-      className={[styles.card, footer !== undefined ? styles.withFooter : '', className]
+      onClick={onClick}
+      className={[
+        styles.card,
+        footer !== undefined ? styles.withFooter : '',
+        onClick ? styles.hoverable : '',
+        className,
+      ]
         .filter(Boolean)
         .join(' ')}
     >