refactor: Move spectrum-analyzer.lisp to parenscript/ directory

Organize all Parenscript-generated JavaScript files together in the
parenscript/ module for better code organization.

asteroid.asd

@@ -48,8 +48,8 @@
                              (:file "profile")
                              (:file "users")
                              (:file "admin")
-                             (:file "player")))
-               (:file "spectrum-analyzer")
+                             (:file "player")
+                             (:file "spectrum-analyzer")))
                (:file "stream-media")
                (:file "user-management")
                (:file "playlist-management")