Rewrite btcprice from Clojure to Python FastAPI

Replace the Clojure Kit application with a Python FastAPI app that
produces identical HTML output. WebSocket proxy, Danish number
formatting, and HTMX integration all preserved.

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

Makefile

@@ -1,25 +1,19 @@
 include .env
 export
 
-.PHONY: clean run run-docker repl tailwind test uberjar
+.PHONY: clean run run-docker tailwind test
 
 clean:
-	rm -rf target
+	rm -rf __pycache__ app/__pycache__
 
 run:
-	clj -M:dev -e "(dev-prep!) (go)" -r
+	.venv/bin/uvicorn app.main:app --host 0.0.0.0 --port 4000 --reload
 
-run-docker:
-	BTCDATA_URL=http://localhost:4101 clj -M:dev -e "(dev-prep!) (go)" -r
-
-repl:
-	clj -M:dev:nrepl
+run-local:
+	BTCDATA_URL=$(BTCDATA_LOCAL_URL) .venv/bin/uvicorn app.main:app --host 0.0.0.0 --port 4000 --reload
 
 tailwind:
 	npm run css:watch
 
 test:
-	clj -M:test
-
-uberjar:
-	clj -T:build all
+	.venv/bin/python -m pytest tests/