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/service/service_test.py

@@ -0,0 +1,118 @@
+import asyncio
+import pytest
+from cpl.core.service.hosted_service import HostedService
+from cpl.core.service.startup_task import StartupTask
+from cpl.core.service.cronjob import CronjobABC
+from cpl.core.time.cron import Cron
+
+# --- HostedService ---
+
+
+def test_hosted_service_cannot_instantiate():
+    with pytest.raises(TypeError):
+        HostedService()
+
+
+def test_hosted_service_concrete_can_start_stop():
+    class MyService(HostedService):
+        def __init__(self):
+            self.started = False
+            self.stopped = False
+
+        async def start(self):
+            self.started = True
+
+        async def stop(self):
+            self.stopped = True
+
+    async def run():
+        svc = MyService()
+        await svc.start()
+        assert svc.started is True
+        await svc.stop()
+        assert svc.stopped is True
+
+    asyncio.run(run())
+
+
+# --- StartupTask ---
+
+
+def test_startup_task_cannot_instantiate():
+    with pytest.raises(TypeError):
+        StartupTask()
+
+
+def test_startup_task_concrete_runs():
+    class MyTask(StartupTask):
+        def __init__(self):
+            self.ran = False
+
+        async def run(self):
+            self.ran = True
+
+    async def execute():
+        task = MyTask()
+        await task.run()
+        assert task.ran is True
+
+    asyncio.run(execute())
+
+
+# --- CronjobABC ---
+
+
+def test_cronjob_cannot_instantiate():
+    with pytest.raises(TypeError):
+        CronjobABC(Cron("* * * * *"))
+
+
+@pytest.mark.asyncio
+async def test_cronjob_loop_is_called():
+    loop_calls = []
+
+    class MyCronJob(CronjobABC):
+        def __init__(self):
+            CronjobABC.__init__(self, Cron("* * * * *"))
+
+        async def loop(self):
+            loop_calls.append(1)
+
+    job = MyCronJob()
+    assert job._running is False
+    await job.start()
+    assert job._running is True
+    # Give it a moment then stop
+    await asyncio.sleep(0.05)
+    await job.stop()
+    assert job._running is False
+
+
+@pytest.mark.asyncio
+async def test_cronjob_stop_cancels_task():
+    class MyCronJob(CronjobABC):
+        def __init__(self):
+            CronjobABC.__init__(self, Cron("* * * * *"))
+
+        async def loop(self):
+            pass
+
+    job = MyCronJob()
+    await job.start()
+    assert job._task is not None
+    await job.stop()
+    assert job._task.cancelled() or job._task.done()
+
+
+@pytest.mark.asyncio
+async def test_cronjob_stop_without_start():
+    class MyCronJob(CronjobABC):
+        def __init__(self):
+            CronjobABC.__init__(self, Cron("* * * * *"))
+
+        async def loop(self):
+            pass
+
+    job = MyCronJob()
+    # stop without start should not raise
+    await job.stop()