feat: add TodoMVC example with editorial design

Full TodoMVC implementation using Pocketbook's synced atom:
- Add, toggle, edit (double-click), destroy todos
- Filter: All / Active / Completed
- Toggle all, clear completed
- Live sync status indicator (online/offline/pending)
- Data persists in IndexedDB, syncs to server via Transit

Design: Ink & Paper aesthetic — cream paper background with grain
texture, Instrument Serif italic header, Newsreader body text,
DM Mono UI chrome, terracotta accent with green completion marks,
deckled left border on card.

Also:
- Server now serves static files from resources/public (/ → todomvc.html)
- Fix CLJS compilation: resolve close!/put! naming conflicts with
  core.async, use qualified async/close!, add clojure.string require
- Fix unbalanced parens in do-pull!
- Remove old placeholder example

test/pocketbook/server_test.clj

@@ -61,14 +61,14 @@
 ;; Tests
 ;; ---------------------------------------------------------------------------
 
-(deftest health-check
+(deftest serves-static-root
   (let [req  (-> (HttpRequest/newBuilder)
                  (.uri (URI. (url "/")))
                  (.GET)
                  (.build))
         resp (.send client req (HttpResponse$BodyHandlers/ofString))]
     (is (= 200 (.statusCode resp)))
-    (is (= "pocketbook ok" (.body resp)))))
+    (is (.contains (.body resp) "TodoMVC"))))
 
 (deftest push-and-pull
   (testing "Push new documents"