Add :effects annotations to boundary.sx IO and signal primitives

All 11 define-io-primitive entries now declare :effects [io].
Signal primitives annotated: signal/deref/computed = [] (pure),
reset!/swap!/effect/batch = [mutation].

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

shared/sx/ref/boundary.sx

@@ -12,6 +12,7 @@
 ;;   (define-io-primitive "name"
 ;;     :params (param1 param2 &key ...)
 ;;     :returns "type"
+;;     :effects [io]
 ;;     :async true
 ;;     :doc "description"
 ;;     :context :request)
@@ -38,6 +39,7 @@
 (define-io-primitive "current-user"
   :params ()
   :returns "dict?"
+  :effects [io]
   :async true
   :doc "Current authenticated user dict, or nil."
   :context :request)
@@ -45,6 +47,7 @@
 (define-io-primitive "request-arg"
   :params (name &rest default)
   :returns "any"
+  :effects [io]
   :async true
   :doc "Read a query string argument from the current request."
   :context :request)
@@ -52,6 +55,7 @@
 (define-io-primitive "request-path"
   :params ()
   :returns "string"
+  :effects [io]
   :async true
   :doc "Current request path."
   :context :request)
@@ -59,6 +63,7 @@
 (define-io-primitive "request-view-args"
   :params (key)
   :returns "any"
+  :effects [io]
   :async true
   :doc "Read a URL view argument from the current request."
   :context :request)
@@ -66,6 +71,7 @@
 (define-io-primitive "csrf-token"
   :params ()
   :returns "string"
+  :effects [io]
   :async true
   :doc "Current CSRF token string."
   :context :request)
@@ -73,6 +79,7 @@
 (define-io-primitive "abort"
   :params (status &rest message)
   :returns "nil"
+  :effects [io]
   :async true
   :doc "Raise HTTP error from SX."
   :context :request)
@@ -82,6 +89,7 @@
 (define-io-primitive "url-for"
   :params (endpoint &key)
   :returns "string"
+  :effects [io]
   :async true
   :doc "Generate URL for a named endpoint."
   :context :request)
@@ -89,6 +97,7 @@
 (define-io-primitive "route-prefix"
   :params ()
   :returns "string"
+  :effects [io]
   :async true
   :doc "Service URL prefix for dev/prod routing."
   :context :request)
@@ -98,6 +107,7 @@
 (define-io-primitive "app-url"
   :params (service &rest path)
   :returns "string"
+  :effects [io]
   :async false
   :doc "Full URL for a service: (app-url \"blog\" \"/my-post/\")."
   :context :config)
@@ -105,6 +115,7 @@
 (define-io-primitive "asset-url"
   :params (&rest path)
   :returns "string"
+  :effects [io]
   :async false
   :doc "Versioned static asset URL."
   :context :config)
@@ -112,6 +123,7 @@
 (define-io-primitive "config"
   :params (key)
   :returns "any"
+  :effects [io]
   :async false
   :doc "Read a value from host configuration."
   :context :config)
@@ -138,11 +150,13 @@
 (declare-signal-primitive "signal"
   :params (initial-value)
   :returns "signal"
+  :effects []
   :doc "Create a reactive signal container with an initial value.")
 
 (declare-signal-primitive "deref"
   :params (signal)
   :returns "any"
+  :effects []
   :doc "Read a signal's current value. In a reactive context (inside an island),
         subscribes the current DOM binding to the signal. Outside reactive
         context, just returns the value.")
@@ -150,23 +164,27 @@
 (declare-signal-primitive "reset!"
   :params (signal value)
   :returns "nil"
+  :effects [mutation]
   :doc "Set a signal to a new value. Notifies all subscribers.")
 
 (declare-signal-primitive "swap!"
   :params (signal f &rest args)
   :returns "nil"
+  :effects [mutation]
   :doc "Update a signal by applying f to its current value. (swap! s inc)
         is equivalent to (reset! s (inc (deref s))) but atomic.")
 
 (declare-signal-primitive "computed"
   :params (compute-fn)
   :returns "signal"
+  :effects []
   :doc "Create a derived signal that recomputes when its dependencies change.
         Dependencies are discovered automatically by tracking deref calls.")
 
 (declare-signal-primitive "effect"
   :params (effect-fn)
   :returns "lambda"
+  :effects [mutation]
   :doc "Run a side effect that re-runs when its signal dependencies change.
         Returns a dispose function. If the effect function returns a function,
         it is called as cleanup before the next run.")
@@ -174,5 +192,6 @@
 (declare-signal-primitive "batch"
   :params (thunk)
   :returns "any"
+  :effects [mutation]
   :doc "Group multiple signal writes. Subscribers are notified once at the end,
         after all values have been updated.")