docs(nav): add SDK architecture link for agent-server to left nav

Place agent-server at the end of the SDK Components section for consistent ordering.

Co-authored-by: openhands <[email protected]>

Author: enyst

docs.json

@@ -280,7 +280,8 @@
                   "sdk/arch/llm",
                   "sdk/arch/skill",
                   "sdk/arch/condenser",
-                  "sdk/arch/security"
+                  "sdk/arch/security",
+                  "sdk/arch/agent-server"
                 ]
               }
             ]