feat: implement Pocketbook — a Clojure-native synced atom

Offline-first key-value store with atom interface (swap!, deref,
add-watch) that syncs to a SQLite-backed server over Transit.

Server (CLJ):
- SQLite storage with Nippy serialization preserving all Clojure types
- GET /sync?group=G&since=T pull endpoint with prefix-based groups
- POST /sync push endpoint with per-document version checking
- Conflict detection (stale write rejection)
- Token-based auth with per-user group access
- CORS support, soft deletes, purge compaction

Client (CLJS):
- IndexedDB wrapper with Transit serialization
- SyncedAtom implementing IAtom (IDeref, ISwap, IReset, IWatchable)
- Write-through to IndexedDB on every swap!
- Background sync loop (pull + push) with configurable interval
- Online/offline detection with reconnect sync
- Conflict resolution (accept server value)
- ready? channel for initial load
- Custom cache atom support (Reagent ratom compatible)

25 tests, 77 assertions across db, transit, server, and auth.

deps.edn

@@ -0,0 +1,26 @@
+{:paths ["src" "resources"]
+ :deps  {org.clojure/clojure          {:mvn/version "1.12.0"}
+         http-kit/http-kit             {:mvn/version "2.8.0"}
+         com.cognitect/transit-clj     {:mvn/version "1.0.333"}
+         com.taoensso/nippy            {:mvn/version "3.4.2"}
+         com.github.seancorfield/next.jdbc {:mvn/version "1.3.955"}
+         org.xerial/sqlite-jdbc        {:mvn/version "3.47.1.0"}
+         ring/ring-core                {:mvn/version "1.13.0"}}
+
+ :aliases
+ {:dev    {:extra-paths ["test"]
+           :extra-deps  {io.github.cognitect-labs/test-runner
+                         {:git/tag "v0.5.1" :git/sha "dfb30dd"}}}
+  :test   {:main-opts ["-m" "cognitect.test-runner"]}
+  :server {:main-opts ["-m" "pocketbook.server"]}
+
+  ;; ClojureScript client build
+  :cljs   {:extra-deps {org.clojure/clojurescript {:mvn/version "1.11.132"}
+                         com.cognitect/transit-cljs {:mvn/version "0.8.280"}
+                         org.clojure/core.async     {:mvn/version "1.7.701"}}
+           :main-opts  ["-m" "cljs.main" "-co" "build.edn" "-c"]}
+
+  :cljs-dev {:extra-deps {org.clojure/clojurescript {:mvn/version "1.11.132"}
+                           com.cognitect/transit-cljs {:mvn/version "0.8.280"}
+                           org.clojure/core.async     {:mvn/version "1.7.701"}}
+             :main-opts  ["-m" "cljs.main" "-co" "build.edn" "-w" "src" "-c"]}}}