Add (param :as type) annotations to all fn/lambda params across SX spec

Extend the type annotation system from defcomp-only to fn/lambda params:
- Infrastructure: sf-lambda, py/js-collect-params-loop, and bootstrap_py.py
  now recognize (name :as type) in param lists, extracting just the name
- bootstrap_py.py: add _extract_param_name() helper, fix _emit_for_each_stmt
- 521 type annotations across 22 .sx spec files (eval, types, adapters,
  transpilers, engine, orchestration, deps, signals, router, prove, etc.)
- Zero behavioral change: annotations are metadata for static analysis only
- All bootstrappers (Python, JS, G1) pass, 81/81 spec tests pass

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

shared/sx/ref/adapter-sx.sx

@@ -12,7 +12,7 @@
 
 
 (define render-to-sx
-  (fn (expr env)
+  (fn (expr (env :as dict))
     (let ((result (aser expr env)))
       ;; aser-call already returns serialized SX strings;
       ;; only serialize non-string values
@@ -21,7 +21,7 @@
         (serialize result)))))
 
 (define aser
-  (fn (expr env)
+  (fn (expr (env :as dict))
     ;; Evaluate for SX wire format — serialize rendering forms,
     ;; evaluate control flow and function calls.
     (set-render-active! true)
@@ -52,7 +52,7 @@
 
 
 (define aser-list
-  (fn (expr env)
+  (fn ((expr :as list) (env :as dict))
     (let ((head (first expr))
           (args (rest expr)))
       (if (not (= (type-of head) "symbol"))
@@ -104,7 +104,7 @@
 
 
 (define aser-fragment
-  (fn (children env)
+  (fn ((children :as list) (env :as dict))
     ;; Serialize (<> child1 child2 ...) to sx source string
     ;; Must flatten list results (e.g. from map/filter) to avoid nested parens
     (let ((parts (list)))
@@ -126,7 +126,7 @@
 
 
 (define aser-call
-  (fn (name args env)
+  (fn ((name :as string) (args :as list) (env :as dict))
     ;; Serialize (name :key val child ...) — evaluate args but keep as sx
     ;; Uses for-each + mutable state (not reduce) so bootstrapper emits for-loops
     ;; that can contain nested for-each for list flattening.
@@ -177,11 +177,11 @@
         "some" "every?" "for-each"))
 
 (define special-form?
-  (fn (name)
+  (fn ((name :as string))
     (contains? SPECIAL_FORM_NAMES name)))
 
 (define ho-form?
-  (fn (name)
+  (fn ((name :as string))
     (contains? HO_FORM_NAMES name)))
 
 
@@ -194,7 +194,7 @@
 ;; Definition forms evaluate for side effects and return nil.
 
 (define aser-special
-  (fn (name expr env)
+  (fn ((name :as string) (expr :as list) (env :as dict))
     (let ((args (rest expr)))
       (cond
         ;; if — evaluate condition, aser chosen branch
@@ -314,7 +314,7 @@
 
 ;; Helper: case dispatch for aser mode
 (define eval-case-aser
-  (fn (match-val clauses env)
+  (fn (match-val (clauses :as list) (env :as dict))
     (if (< (len clauses) 2)
       nil
       (let ((test (first clauses))