test(systems): move the name-gate cases to the service the gate moved into (#3028)

Two tests further down test_mcp_tool_systems.py still drove the gate through
the tool — `svc.list_systems` stubbed, the tool doing the normalising — so the
new `await systems_svc.assess_system_name(...)` hit an unstubbed MagicMock.

Stubbing them at the tool would have kept testing the wrong layer. The
normalisation cases belong with the logic, so they move to
tests/test_services_systems.py as real coverage of assess_system_name: case and
whitespace folding, exact-beats-overlap (and that an exact hit short-circuits
the lesser lookup), no invented match, fail-open on both arms, and silence for a
nameless system.

What stays the tool's job — rendering a duplicate, applying an exact area,
offering an overlap — is already covered at the top of that file.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/test_mcp_tool_systems.py

@@ -243,33 +243,11 @@ async def test_populated_vocabulary_never_counts_records():
     notes.list_notes.assert_not_awaited()
 
 
-@pytest.mark.asyncio
-async def test_create_system_same_normalized_name_is_duplicate_gated():
-    existing = fake_system(id=7, name="Scrape Pipeline")
-    existing.id = 7
-    existing.name = "Scrape Pipeline"
-    with patch("scribe.mcp.tools.systems.current_user_id", return_value=1), \
-         patch("scribe.mcp.tools.systems.systems_svc") as svc:
-        svc.list_systems = AsyncMock(return_value=[existing])
-        svc.create_system = AsyncMock()
-        from scribe.mcp.tools.systems import create_system
-        result = await create_system(project_id=5, name="  scrape   pipeline ")
-    assert result["duplicate"] is True
-    assert result["existing_id"] == 7
-    svc.create_system.assert_not_awaited()
-
-
-@pytest.mark.asyncio
-async def test_create_system_distinct_name_passes_the_gate():
-    other = fake_system(id=7, name="Workers")
-    other.name = "Workers"
-    with patch("scribe.mcp.tools.systems.current_user_id", return_value=1), \
-         patch("scribe.mcp.tools.systems.systems_svc") as svc:
-        svc.list_systems = AsyncMock(return_value=[other])
-        svc.create_system = AsyncMock(return_value=fake_system(id=8, name="Exporter"))
-        from scribe.mcp.tools.systems import create_system
-        result = await create_system(project_id=5, name="Exporter")
-    assert result["name"] == "Exporter"
+# The name gate's own cases (case/whitespace normalisation, exact-over-overlap,
+# fail-open) moved to tests/test_services_systems.py with the logic itself —
+# services/systems.assess_system_name, so both doors share one answer (#2482).
+# What stays the TOOL's job — rendering a duplicate, applying an exact area,
+# offering an overlap — is covered at the top of this file.
 
 
 @pytest.mark.asyncio