Add real-time BTC price feed via Binance WebSocket

Connect to Binance trade stream, persist prices to binance_price table
(throttled to every 5s), and live-update the home page via HTMX polling.

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

resources/queries.sql

@@ -1,2 +1,9 @@
 -- queries for btcprice
--- Add HugSQL queries here as tables are created
+
+-- :name insert-binance-price! :! :n
+-- :doc Insert a Binance BTC price
+INSERT INTO binance_price (price) VALUES (:price)
+
+-- :name get-latest-binance-price :? :1
+-- :doc Get the most recent Binance BTC price
+SELECT price, recorded_at FROM binance_price ORDER BY id DESC LIMIT 1