Render price and strike HTML in btcprice from btcdata JSON WebSockets

Receive raw JSON from btcdata, transform to HTML in ws_proxy.clj.
Added data.json dependency, price and strike rendering, safelist updates.

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

deps.edn

@@ -25,7 +25,8 @@
 
         ;; Serialization
         metosin/muuntaja                     {:mvn/version "0.6.11"}
-        luminus-transit/luminus-transit       {:mvn/version "0.1.6"}}
+        luminus-transit/luminus-transit       {:mvn/version "0.1.6"}
+        org.clojure/data.json                {:mvn/version "2.5.1"}}
 
  :aliases
  {:build {:deps {io.github.clojure/tools.build {:mvn/version "0.10.9"}}