Refactor entrypoint script to use Python and streamline environment variable handling

Co-authored-by: Copilot <copilot@github.com>

docker/entrypoint.sh

@@ -1,27 +1,27 @@
-#!/bin/sh
-set -eu
+#!/usr/bin/env python3
+import os
+import sys
+from pathlib import Path
 
-mkdir -p /app/archive /app/config /app/bin/temp
 
-if [ -z "${CLIENT_ID:-}" ]; then
-	client_id_from_hyphenated="$(printenv 'CLIENT-ID' 2>/dev/null || true)"
-	if [ -n "$client_id_from_hyphenated" ]; then
-		export CLIENT_ID="$client_id_from_hyphenated"
-	fi
-fi
+for path in ('/app/archive', '/app/config', '/app/bin/temp'):
+	Path(path).mkdir(parents=True, exist_ok=True)
 
-if [ -z "${CLIENT_SECRET:-}" ]; then
-	client_secret_from_hyphenated="$(printenv 'CLIENT-SECRET' 2>/dev/null || true)"
-	if [ -n "$client_secret_from_hyphenated" ]; then
-		export CLIENT_SECRET="$client_secret_from_hyphenated"
-	fi
-fi
 
-if [ -z "${OAUTH_PRIVATE_TOKEN:-}" ]; then
-	oauth_token_from_hyphenated="$(printenv 'OAUTH-PRIVATE-TOKEN' 2>/dev/null || true)"
-	if [ -n "$oauth_token_from_hyphenated" ]; then
-		export OAUTH_PRIVATE_TOKEN="$oauth_token_from_hyphenated"
-	fi
-fi
+env_aliases = {
+	'CLIENT-ID': 'CLIENT_ID',
+	'CLIENT-SECRET': 'CLIENT_SECRET',
+	'OAUTH-PRIVATE-TOKEN': 'OAUTH_PRIVATE_TOKEN',
+}
 
-exec "$@"
+for source_name, target_name in env_aliases.items():
+	source_value = os.environ.get(source_name)
+	if source_value and not os.environ.get(target_name):
+		os.environ[target_name] = source_value
+
+
+if len(sys.argv) < 2:
+	raise SystemExit('twitch-archive-entrypoint requires a command to run')
+
+
+os.execvpe(sys.argv[1], sys.argv[1:], os.environ)