Remove alpha toggle demo from todomvc example

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Mike Thompson

examples/todomvc/src/todomvc/events.cljs

@@ -207,17 +207,3 @@
      (reduce #(assoc-in %1 [%2 :done] new-done)
              todos
              (keys todos)))))
-
-;; TODO: I'd like to do this.
-;; I think it requires the :alpha subscription to have a :set method.
-#_(reg :event :toggle-alpha :<- :alpha? :-> not)
-
-(reg-event-db
- :toggle-alpha
- (fn [db _]
-   ;; don't need to know the path any more.
-   ;; can compute the sub instead.
-   ;; it's memory-safe.
-   (let [alpha? @(sub :alpha?)]
-     ;; still need to know the path to update the value.
-     (update-in db [:very :long :path :alpha?] not))))

examples/todomvc/src/todomvc/subs.cljs

@@ -160,5 +160,3 @@
  :<- [:completed-count]
  (fn [[todos completed] _]
    [(- (count todos) completed) completed]))
-
-(reg :sub :alpha? :-> (comp :alpha? :path :long :very))

examples/todomvc/src/todomvc/views.cljs

@@ -91,17 +91,9 @@
      :on-save #(when (seq %)
                  (dispatch [:add-todo %]))}]])
 
-(defn alpha []
-  (let [alpha? @(sub :alpha?)]
-    [:a {:href "#"
-         :style {:color (if alpha? "red" "gray")}
-         :on-click #(dispatch [:toggle-alpha])}
-     (if alpha? "alpha is running!" "try alpha?")]))
-
 (defn todo-app
   []
   [:<>
-   [alpha]
    [:section#todoapp
     [task-entry]
     (when (seq @(subscribe [:todos]))