refactor: Pipeline-Stufen in Ordner mit ihren Prompts

Im Wurzelverzeichnis liegt nur noch TextToModel.py (Ablauf und CLI).
Jede Stufe liegt mit Code und Prompt in einem eigenen Ordner: core,
understanding, modeling, checks, solving, reporting, data, benchmark;
Tests unter tests/, Aufgaben unter tasks/. understand_task,
text_to_model/revise_model und review_assumptions/needs_work/select_best
sind aus TextToModel.py zu ihren Prompts gewandert, inhaltlich
unveraendert. Prompt-Kennung des Benchmarks bleibt 93744636095a.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/test_charts.py

@@ -0,0 +1,138 @@
+"""Inline-SVG-Diagramme: gültiges SVG, korrekte Geometrie, Einbindung in den Report."""
+import xml.etree.ElementTree as ET
+
+import pytest
+
+from reporting import charts
+from core.model_schema import PipelineResult, ResultTable, SolverRun, SolverStatus
+from reporting.report import build_document, to_html, to_markdown
+from test_model_checks import make_spec
+from test_result_tables import PORTFOLIO_TABLE
+from test_review import make_review
+
+LABELS = ["A02", "A08", "A03"]
+VALUES = [0.03433, 0.03093, 0.02587]
+
+
+def parse(svg: str):
+    assert svg.startswith("<svg")
+    return ET.fromstring(svg)
+
+
+def test_bar_chart_is_valid_svg_with_one_bar_per_label():
+    root = parse(charts.bar_chart(LABELS, VALUES, "Portfolio"))
+    assert len(root.findall(".//{http://www.w3.org/2000/svg}path")) == len(LABELS)
+    texts = [t.text for t in root.findall(".//{http://www.w3.org/2000/svg}text")]
+    for label in LABELS:
+        assert label in texts  # Direktbeschriftung statt Legende (eine Serie)
+    assert root.get("role") == "img" and "Portfolio" in root.get("aria-label")
+
+
+def test_bars_are_proportional_and_capped_in_thickness():
+    svg = charts.bar_chart(["groß", "klein"], [1.0, 0.5], "Test")
+    widths = [float(d.split("H")[1].split(" ")[0].split(",")[0]) for d in
+              [p.get("d") for p in parse(svg).findall(".//{http://www.w3.org/2000/svg}path")]]
+    assert widths[0] > widths[1]
+    heights = {float(p.get("d").split("V")[1].split(" ")[0]) for p in parse(svg).findall(".//{http://www.w3.org/2000/svg}path")}
+    assert charts.BAR_HEIGHT <= 24
+
+
+def test_negative_values_use_the_other_colour_role():
+    svg = charts.bar_chart(["Ertrag", "Kosten"], [1.0, -0.4], "Test")
+    fills = [p.get("fill") for p in parse(svg).findall(".//{http://www.w3.org/2000/svg}path")]
+    assert fills == ["var(--viz-pos)", "var(--viz-neg)"]
+
+
+def test_waterfall_has_step_per_term_plus_total():
+    svg = charts.waterfall_chart(["Rendite", "Risiko", "Kosten"], [0.1277, -0.0052, -0.0256],
+                                 "Zielwert", 0.0969, "Zielwert-Zerlegung", " ")
+    root = parse(svg)
+    fills = [p.get("fill") for p in root.findall(".//{http://www.w3.org/2000/svg}path")]
+    assert fills == ["var(--viz-pos)", "var(--viz-neg)", "var(--viz-neg)", "var(--viz-total)"]
+    assert "Zielwert" in [t.text for t in root.findall(".//{http://www.w3.org/2000/svg}text")]
+
+
+def test_tooltip_per_mark():
+    root = parse(charts.bar_chart(LABELS, VALUES, "Portfolio"))
+    titles = [t.text for t in root.findall(".//{http://www.w3.org/2000/svg}title")]
+    assert len(titles) == len(LABELS) and titles[0].startswith("A02: ")
+
+
+def make_result(tables):
+    return PipelineResult(
+        task="Aufgabe", specification=make_spec(), review=make_review(), revisions=0,
+        solver_run=SolverRun(status=SolverStatus.OPTIMAL, objective_value=0.09756, tables=tables,
+                             headline="Das Portfolio erreicht 9,76 %.", solution={"w[A02]": 0.3}),
+    )
+
+
+def test_html_report_embeds_chart_and_markdown_does_not():
+    doc = build_document(make_result([ResultTable.model_validate(PORTFOLIO_TABLE)]))
+    page = to_html(doc)
+    assert '<figure class="viz-root">' in page and "<svg" in page
+    assert "<svg" not in to_markdown(doc)
+
+
+def test_decomposition_table_gets_waterfall():
+    table = ResultTable(title="Zielwert-Zerlegung", columns=["Bestandteil", "Wert"],
+                        rows=[["Rendite", 0.1277], ["Risiko", -0.0052], ["Kosten", -0.0256], ["Zielwert", 0.0969]],
+                        objective_column="Wert")
+    page = to_html(build_document(make_result([table])))
+    assert page.count("var(--viz-total)") == 1  # Gesamtbalken nur im Wasserfall
+
+
+def test_result_comes_first_and_headline_is_lead():
+    doc = build_document(make_result([ResultTable.model_validate(PORTFOLIO_TABLE)]))
+    h2 = [b[1] for b in doc if b[0] == "h2"]
+    assert h2[0] == "Ergebnis" and h2.index("Ergebnis") < h2.index("Mathematisches Modell")
+    assert ("lead", "Das Portfolio erreicht 9,76 %.") in doc
+    assert '<p class="lead">' in to_html(doc)
+
+
+@pytest.mark.parametrize("table", [
+    ResultTable(title="Ohne Zahlen", columns=["A", "B"], rows=[["x", "1,5 %"]], objective_column="B"),
+    ResultTable(title="Nur eine Zeile", columns=["A", "B"], rows=[["x", 1.0]], objective_column="B"),
+    ResultTable(title="Ohne Beitragsspalte", columns=["A", "B"], rows=[["x", 1.0], ["y", 2.0]]),
+])
+def test_no_chart_without_usable_numbers(table):
+    assert "<svg" not in to_html(build_document(make_result([table])))
+
+
+# --- Graphenzeichnung ---
+
+def test_graph_chart_is_valid_svg_and_marks_the_path():
+    import xml.etree.ElementTree as ET
+    from reporting.charts import graph_chart
+    svg = graph_chart(["0", "1", "2", "3"],
+                      [("0", "1", 8), ("0", "2", 18), ("0", "3", 31), ("1", "2", 10), ("1", "3", 21), ("2", "3", 12)],
+                      path=["0", "1", "3"], title="Graph")
+    ET.fromstring(svg)
+    assert svg.count("<circle") == 4          # jeder Knoten einmal
+    assert svg.count("marker-end") == 6        # jeder Bogen einmal, und gerichtet
+    assert svg.count("--viz-pos") >= 2         # Weg und Knoten des Weges hervorgehoben
+
+
+def test_graph_chart_refuses_unknown_nodes_and_huge_graphs():
+    from reporting.charts import graph_chart
+    assert graph_chart(["a"], [("a", "b", 1)]) == ""                    # Bogen ins Nichts
+    assert graph_chart([str(i) for i in range(20)], [("0", "1", 1)]) == ""  # zu groß zum Zeichnen
+    assert graph_chart([], []) == ""
+
+
+def test_graph_section_explains_before_it_shows():
+    from core.model_schema import GraphSolution, SolverRun, SolverStatus
+    from reporting.report import _graph_section
+    run = SolverRun(status=SolverStatus.OPTIMAL, objective_value=29, graph=GraphSolution.model_validate({
+        "nodes": ["0", "1", "3"],
+        "arcs": [{"source": "0", "target": "1", "weight": 8}, {"source": "1", "target": "3", "weight": 21}],
+        "path": ["0", "1", "3"],
+        "steps": [{"node": "0", "label": 0}, {"node": "1", "label": 8}, {"node": "3", "label": 29}],
+        "node_meaning": "ein Zeitpunkt – das Ende von Jahr i.",
+        "arc_meaning": "Kauf am Ende von Jahr i und Nutzung bis Ende von Jahr j.",
+    }))
+    doc = _graph_section(run)
+    arten = [block[0] for block in doc]
+    assert arten[0] == "p" and "Ende von Jahr" in doc[0][1]   # Erklärung steht vor der Zeichnung
+    assert "svg" in arten
+    assert any(b[0] == "table" and "Markierungsverlauf" in str(doc[arten.index("table") - 1]) for b in doc)
+    assert any("8 + 21 = 29" in str(b) for b in doc)          # Rechenweg ausgeschrieben