feat(logging): implement configurable belief state logging

- Add LoggingConfig model and logging field to GlobalSettings
- Implement belief_scope context manager for structured logging
- Add configure_logger for dynamic level and file rotation settings
- Add logging configuration UI to Settings page
- Update ConfigManager to apply logging settings on initialization and updates

backend/tests/test_logger.py

@@ -0,0 +1,44 @@
+import pytest
+from backend.src.core.logger import belief_scope, logger
+
+
+def test_belief_scope_logs_entry_action_exit(caplog):
+    """Test that belief_scope generates [ID][Entry], [ID][Action], and [ID][Exit] logs."""
+    caplog.set_level("INFO")
+
+    with belief_scope("TestFunction"):
+        logger.info("Doing something important")
+
+    # Check that the logs contain the expected patterns
+    log_messages = [record.message for record in caplog.records]
+
+    assert any("[TestFunction][Entry]" in msg for msg in log_messages), "Entry log not found"
+    assert any("[TestFunction][Action] Doing something important" in msg for msg in log_messages), "Action log not found"
+    assert any("[TestFunction][Exit]" in msg for msg in log_messages), "Exit log not found"
+
+
+def test_belief_scope_error_handling(caplog):
+    """Test that belief_scope logs Coherence:Failed on exception."""
+    caplog.set_level("INFO")
+
+    with pytest.raises(ValueError):
+        with belief_scope("FailingFunction"):
+            raise ValueError("Something went wrong")
+
+    log_messages = [record.message for record in caplog.records]
+
+    assert any("[FailingFunction][Entry]" in msg for msg in log_messages), "Entry log not found"
+    assert any("[FailingFunction][Coherence:Failed]" in msg for msg in log_messages), "Failed coherence log not found"
+    # Exit should not be logged on failure
+
+
+def test_belief_scope_success_coherence(caplog):
+    """Test that belief_scope logs Coherence:OK on success."""
+    caplog.set_level("INFO")
+
+    with belief_scope("SuccessFunction"):
+        pass
+
+    log_messages = [record.message for record in caplog.records]
+
+    assert any("[SuccessFunction][Coherence:OK]" in msg for msg in log_messages), "Success coherence log not found"