Add clickable host bios linking to host detail pages on Nuggets; v2.0.21

Each host card on /nuggets now links to /nuggets/hosts/:hostId showing
the host's full photo, bio, and listen links. Archived hosts return a
graceful "not found" page with a back link.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -1,7 +1,7 @@
 {
   "name": "siteforge",
   "private": true,
-  "version": "2.0.20",
+  "version": "2.0.21",
   "type": "module",
   "scripts": {
     "dev": "vite",