Add :effects annotations to all spec files and update bootstrappers

Bootstrappers (bootstrap_py.py, js.sx) now skip :effects keyword in
define forms, enabling effect annotations throughout the spec without
changing generated output.

Annotated 180+ functions across 14 spec files:
- signals.sx: signal/deref [] pure, reset!/swap!/effect/batch [mutation]
- engine.sx: parse-* [] pure, morph-*/swap-* [mutation io]
- orchestration.sx: all [mutation io] (browser event binding)
- adapter-html.sx: render-* [render]
- adapter-dom.sx: render-* [render], reactive-* [render mutation]
- adapter-sx.sx: aser-* [render]
- adapter-async.sx: async-render-*/async-aser-* [render io]
- parser.sx: all [] pure
- render.sx: predicates [] pure, process-bindings [mutation]
- boot.sx: all [mutation io] (browser init)
- deps.sx: scan-*/transitive-* [] pure, compute-all-* [mutation]
- router.sx: all [] pure (URL matching)

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

shared/static/scripts/sx-browser.js

@@ -14,7 +14,7 @@
   // =========================================================================
 
   var NIL = Object.freeze({ _nil: true, toString: function() { return "nil"; } });
-  var SX_VERSION = "2026-03-11T22:53:48Z";
+  var SX_VERSION = "2026-03-11T23:22:03Z";
 
   function isNil(x) { return x === NIL || x === null || x === undefined; }
   function isSxTruthy(x) { return x !== false && !isNil(x); }