feat(client): add Card header/footer, DescriptionList, and portal ContextMenu

- add Card header prop (primary/secondary variants) and footer prop (sticks to bottom)
- add Breadcrumbs to all 5 pages; remove duplicate h1 headings
- add pageToolbar layout for breadcrumbs + danger button aligned right
- add DescriptionList component replacing raw dl/dt/dd markup; supports truncate+tooltip
- rewrite ContextMenu to render dropdown via React portal to avoid clip/overflow issues
- update EnvironmentCard to use Card header (primary), footer (Timestamp), and truncated DescriptionList
- fix cog button contrast, square sizing, and right-edge alignment on colored header
- add border to Timestamp pill for dark-mode visibility
- add id badge pill styling to environment card header

client/src/pages/Page.module.css

@@ -53,8 +53,25 @@
 
 .envCardId {
   font-size: var(--font-size-xs);
-  color: var(--color-text-muted);
+  font-weight: 700;
+  color: inherit;
   flex-shrink: 0;
+  background: rgba(0, 0, 0, 0.22);
+  border: 1px solid rgba(0, 0, 0, 0.35);
+  border-radius: 9999px;
+  padding: 1px var(--space-2);
+  line-height: 1.6;
+}
+
+.envCardHeader button {
+  color: inherit;
+  padding: var(--space-1);
+  aspect-ratio: 1;
+  margin-right: calc(-1 * var(--space-1));
+}
+
+.envCardHeader button:hover {
+  background: color-mix(in srgb, currentColor 15%, transparent) !important;
 }
 
 .envCardName {