test(core): extend coverage — console, errors, log, service, time, benchmark

Add missing test modules for previously untested core areas:
- console: ForegroundColorEnum, BackgroundColorEnum, Console methods
- errors: dependency_error, module_dependency_error
- log: LogLevel ordering/values, LogSettings, Logger (should_log, format, file write, fatal)
- service: HostedService, StartupTask, CronjobABC (start/stop/loop/task cancellation)
- time: TimeFormatSettings properties and setters
- utils: Benchmark.time / .memory / .all call-count and output

Also fix existing test files: environment cleanup, cron exception specificity,
json_processor kwargs bug doc, configuration_model_abc to_dict bug doc.
All 199 tests pass, black clean.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

test/core/errors_test.py

@@ -0,0 +1,38 @@
+import pytest
+from cpl.core.errors import dependency_error, module_dependency_error
+
+
+def test_dependency_error_exits(capsys):
+    with pytest.raises(SystemExit):
+        dependency_error("my.feature", "some-package")
+
+
+def test_dependency_error_prints_message(capsys):
+    with pytest.raises(SystemExit):
+        dependency_error("my.feature", "some-package")
+    captured = capsys.readouterr()
+    assert "some-package" in captured.out
+    assert "my.feature" in captured.out
+
+
+def test_dependency_error_with_import_error(capsys):
+    try:
+        import nonexistent_package
+    except ImportError as e:
+        with pytest.raises(SystemExit):
+            dependency_error("my.feature", "nonexistent_package", e)
+        captured = capsys.readouterr()
+        assert "nonexistent_package" in captured.out
+
+
+def test_module_dependency_error_exits(capsys):
+    with pytest.raises(SystemExit):
+        module_dependency_error("MyModule", "SomeDependency")
+
+
+def test_module_dependency_error_prints_message(capsys):
+    with pytest.raises(SystemExit):
+        module_dependency_error("MyModule", "SomeDependency")
+    captured = capsys.readouterr()
+    assert "SomeDependency" in captured.out
+    assert "MyModule" in captured.out