refactor, add modularity

app/config.py

@@ -0,0 +1,11 @@
+import os
+
+REDMINE_URL = os.environ.get("REDMINE_URL", "").rstrip("/")
+REDMINE_API_KEY = os.environ.get("REDMINE_API_KEY", "")
+
+
+def validate():
+    if not REDMINE_URL or not REDMINE_API_KEY:
+        raise RuntimeError(
+            "REDMINE_URL and REDMINE_API_KEY environment variables must be set."
+        )