Add (param :as type) annotations to defcomp params across all services and templates

Annotates ~500 defcomp params across 62 files: market (5), blog (7), cart (5),
events (3), federation (4), account (3), orders (2), shared templates (11),
sx docs (14), plus remaining spec fn params (z3, test-framework, adapter-dom,
adapter-async, engine, eval). Total annotations in codebase: 1043.

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

shared/sx/ref/engine.sx

@@ -151,7 +151,7 @@
 ;; --------------------------------------------------------------------------
 
 (define process-response-headers
-  (fn (get-header)
+  (fn ((get-header :as lambda))
     ;; Extract all SX response header directives into a dict.
     ;; get-header is (fn (name) → string or nil).
     (dict