Add type annotations to remaining untyped spec params

trampoline (eval.sx), signal/deref (signals.sx), aser (adapter-sx.sx).

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

shared/sx/ref/adapter-sx.sx

@@ -21,7 +21,7 @@
         (serialize result)))))
 
 (define aser
-  (fn (expr (env :as dict))
+  (fn ((expr :as any) (env :as dict))
     ;; Evaluate for SX wire format — serialize rendering forms,
     ;; evaluate control flow and function calls.
     (set-render-active! true)