fix(web): stop presenting an unscored case as a failed analysis, and four smaller things

From clicking through the redesigned UI:

- scoring a case without a model registry painted a red failure across a case that had in
  fact analysed fine. It is now a quiet note saying the model term contributes 0, because
  scoring is an optional fourth of the rank, not the analysis.
- the MLflow default moves to port 5001. On macOS, AirPlay Receiver owns 5000, which is why
  the registry answered "403" rather than refusing the connection; docker-compose publishes
  5001 to match.
- a funnel step that kept nothing drew a visible bar. Zero now draws zero.
- "1 candidates".
- the funnel's fixed grid columns forced a horizontal scrollbar on the report.

The report also lists the top undecided candidates now: the first thing anyone opens has no
decisions in it, and "Shortlisted (0)" alone said nothing about what the tool found.

Tests: api 77, web 32; ruff, mypy, svelte-check clean.

api/tests/test_cases.py

@@ -113,6 +113,30 @@ async def test_the_report_is_the_decision_trail(client: AsyncClient) -> None:
     assert report["provenance"]["vep_version"] == "113.0"
 
 
+@pytest.mark.usefixtures("db")
+async def test_the_report_shows_the_top_candidates_before_anyone_decides(
+    client: AsyncClient,
+) -> None:
+    """The first thing anyone opens is a report with no decisions in it; it must still say something."""
+    case_id, _ = await a_case_with_candidates()
+
+    report = (await client.get(f"/api/cases/{case_id}/report")).json()
+    assert report["shortlisted"] == []
+    assert [c["variant"]["gene"] for c in report["top"]] == ["NF2", "CHEK2"]
+
+
+@pytest.mark.usefixtures("db")
+async def test_the_report_drops_decided_variants_from_the_top_list(client: AsyncClient) -> None:
+    case_id, _ = await a_case_with_candidates()
+    items = (await client.get(f"/api/cases/{case_id}/candidates")).json()["items"]
+    await client.post(f"/api/variants/{items[0]['variant']['id']}/decision",
+                      json={"state": "shortlisted", "reason": "fits"})
+
+    report = (await client.get(f"/api/cases/{case_id}/report")).json()
+    assert [c["variant"]["gene"] for c in report["shortlisted"]] == ["NF2"]
+    assert [c["variant"]["gene"] for c in report["top"]] == ["CHEK2"]
+
+
 @pytest.mark.usefixtures("db")
 async def test_candidates_can_still_be_filtered(client: AsyncClient) -> None:
     case_id, _ = await a_case_with_candidates()