feat(standards): integrate auth-server via pinned spec (docs://spec) + auth recipe and template slice

- serve the pinned auth-server OpenAPI contract as the standards MCP resource docs://spec (no auth-server MCP bundle)
- add Auth Integration recipe (14) and wire it into the registry, prompts, index, and nav
- un-defer Auth Server in the library registry (spec/recipe pointers)
- ship the opt-in template auth slice: interfaces/auth/ (placeholder + mergeable bearerAuth security.yaml) and AUTH_SERVER/JWT_SERVER env
- rebuild bundle (13 modules, 44 components); template stays authless by default

standards/lib/404.html

@@ -457,6 +457,28 @@
   
   
   
+    <li class="md-nav__item">
+      <a href="/14_auth_integration/" class="md-nav__link">
+        
+  
+  
+  <span class="md-ellipsis">
+    Auth Integration
+    
+  </span>
+  
+
+      </a>
+    </li>
+  
+
+    
+      
+      
+  
+  
+  
+  
     <li class="md-nav__item">
       <a href="/13_library_registry/" class="md-nav__link">