feat: transport registry and onboarding updates (#69)

tests/test_transport_registry.py

@@ -0,0 +1,19 @@
+import pytest
+
+from takopi import transports
+from takopi.config import ConfigError
+
+
+def test_transport_registry_lists_telegram() -> None:
+    ids = transports.list_transports()
+    assert "telegram" in ids
+
+
+def test_transport_registry_gets_telegram() -> None:
+    backend = transports.get_transport("telegram")
+    assert backend.id == "telegram"
+
+
+def test_transport_registry_unknown() -> None:
+    with pytest.raises(ConfigError, match="Unknown transport"):
+        transports.get_transport("nope")