Support selectable Aider providers

tests/test_agent.py

@@ -48,6 +48,8 @@ def test_aider_environment_does_not_include_database_credentials(tmp_path, monke
     workspace = tmp_path / "repo"
     (workspace / ".git").mkdir(parents=True)
     monkeypatch.setenv("TEST_DB_PASSWORD", "must-not-reach-aider")
+    monkeypatch.setenv("OPENROUTER_API_KEY", "qwen-provider-key")
+    monkeypatch.setenv("OLLAMA_API_BASE", "http://host.docker.internal:11434")
     captured = {}
 
     def run(command, **kwargs):
@@ -63,4 +65,6 @@ def test_aider_environment_does_not_include_database_credentials(tmp_path, monke
     AiderAgent(config).run(workspace, "fix it")
 
     assert "TEST_DB_PASSWORD" not in captured
-    assert "DB_PASSWORD" not in captured
+    assert "DB_PASSWORD" not in captured
+    assert captured["OPENROUTER_API_KEY"] == "qwen-provider-key"
+    assert captured["OLLAMA_API_BASE"] == "http://host.docker.internal:11434"