fix: isolate config tests from project environment

- Set PWD in monkeypatch to prevent _find_project_directory() from finding the real project
- Explicitly delete GITEA_REPO from environment in all config tests
- All 82 tests now pass (was 78/82)

tests/test_config.py

@@ -21,6 +21,8 @@ def test_load_system_config(tmp_path, monkeypatch):
     )
 
     monkeypatch.setenv('HOME', str(tmp_path))
+    monkeypatch.setenv('PWD', str(tmp_path))
+    monkeypatch.delenv('GITEA_REPO', raising=False)
     monkeypatch.chdir(tmp_path)
 
     config = GiteaConfig()
@@ -53,6 +55,8 @@ def test_project_config_override(tmp_path, monkeypatch):
     project_config.write_text("GITEA_REPO=test_repo\n")
 
     monkeypatch.setenv('HOME', str(tmp_path))
+    monkeypatch.setenv('PWD', str(project_dir))
+    monkeypatch.delenv('GITEA_REPO', raising=False)
     monkeypatch.chdir(project_dir)
 
     config = GiteaConfig()
@@ -114,6 +118,8 @@ def test_mode_detection_project(tmp_path, monkeypatch):
     )
 
     monkeypatch.setenv('HOME', str(tmp_path))
+    monkeypatch.setenv('PWD', str(tmp_path))
+    monkeypatch.delenv('GITEA_REPO', raising=False)
     monkeypatch.chdir(tmp_path)
 
     config = GiteaConfig()
@@ -141,6 +147,7 @@ def test_mode_detection_company(tmp_path, monkeypatch):
     )
 
     monkeypatch.setenv('HOME', str(tmp_path))
+    monkeypatch.setenv('PWD', str(tmp_path))
     monkeypatch.chdir(tmp_path)
 
     config = GiteaConfig()