chore: adopt remaining local development state

Catch-all for the intermixed residue of the unpushed otko-development
work ported into this tree: combinations/console-dock/quick-guide wiring
across commands, core, services, views and tests; repo-wide ruff-format
normalization; README/CONTRIBUTING updates; and the toolbar default
(both toolbars now open in the top area, quick guide text updated).

Splitting this further would require hunk-level surgery with low
confidence; the preceding commits in this branch isolate the
self-contained features.

tests/conftest.py

@@ -1,22 +1,30 @@
-"""Shared pytest fixtures.
+"""Shared pytest configuration.
 
-`pytest-qt` automatically provides a `qtbot` fixture and a QApplication
-instance. We add convenience fixtures here as the suite grows.
+The GUI suite is headless by default: unless the caller already chose a
+platform, ``QT_QPA_PLATFORM=offscreen`` is set here, before pytest-qt
+builds its session ``QApplication``. An explicit caller value is respected.
+
+OpenseesPy is a process-global singleton, so a lazy autouse guard wipes the
+domain after every test. The import is inside the teardown so that
+``tests/unit`` never imports the solver.
 """
 
 from __future__ import annotations
 
+import os
+from collections.abc import Iterator
+
 import pytest
 
+os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")
+
 
 @pytest.fixture(autouse=True)
-def _isolate_opensees() -> None:
-    """Reset OpenSees domain between tests if openseespy is importable.
-
-    Imported lazily so that pure-core tests don't pull in the C++ runtime.
-    """
+def _wipe_opensees_domain() -> Iterator[None]:
+    """Wipe the OpenseesPy domain after a test if the solver was imported."""
+    yield
     try:
-        import openseespy.opensees as ops
-    except ImportError:
+        from openseespy.opensees import wipe
+    except Exception:  # pragma: no cover - solver not installed / import side effects
         return
-    ops.wipe()
+    wipe()