fix(chart): Sripati Bhava from the real sidereal MC; Bhava chart and tables (T5, BUG-1077)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017eEAG8HD3mm8gsKXgk8uU8

tests/test_api_server_security.py

@@ -3281,6 +3281,58 @@ def test_bhava_chalit_endpoint_exposes_user_selected_house_systems() -> None:
         assert result['result']['calculation_note']
 
 
+def _golden_natal_body() -> dict:
+    """Real engine natal packet the chart page uses (fictional 1990-06-15 12:00 Beijing, Raman, mean node)."""
+    golden = json.loads((Path(__file__).resolve().parents[1] / 'frontend/tests/fixtures/chart-view-golden.json').read_text(encoding='utf-8'))
+    chart = golden['chart']
+    return {
+        'planets': {name: {'lon': row['lon']} for name, row in chart['planets'].items()},
+        'ascendant': {'lon': chart['ascendant']['lon']},
+        'year': 1990, 'month': 6, 'day': 15, 'hour': 12, 'minute': 0, 'second': 0,
+        'lat': 39.9042, 'lon': 116.4074, 'tz': 8,
+        'ayanamsa': 'raman',
+        'house_system': 'sripati',
+        'mode': 'compare',
+    }
+
+
+def test_bhava_chalit_sripati_without_mc_or_birth_moment_is_rejected_not_equal_houses() -> None:
+    """BUG-1077: a missing MC used to default to asc+270, silently turning Sripati into equal houses."""
+    body = _golden_natal_body()
+    for key in ('year', 'month', 'day', 'hour', 'minute', 'second', 'lat', 'lon', 'tz'):
+        body.pop(key)
+    with pytest.raises(BadRequest, match='mc_lon'):
+        _handler()._compute_bhava_chalit(body)
+
+
+def test_bhava_chalit_sripati_derives_the_sidereal_mc_from_the_birth_moment() -> None:
+    import swisseph as swe
+    from ayanamsa_utils import temporary_ayanamsa
+
+    body = _golden_natal_body()
+    result = _handler()._compute_bhava_chalit(body)['result']
+    spans = [house['span_degrees'] for house in result['boundaries']['houses']]
+    assert len(spans) == 12
+    # Before BUG-1077 every span was exactly 30.0 (equal houses).
+    assert any(abs(span - 30.0) > 0.1 for span in spans), spans
+
+    jd = swe.julday(1990, 6, 15, 12 - 8)
+    with temporary_ayanamsa('raman', swe):
+        _, ascmc = swe.houses_ex(jd, 39.9042, 116.4074, b'R', swe.FLG_SWIEPH | swe.FLG_SIDEREAL)
+    assert abs(result['mc_lon'] - ascmc[1] % 360) < 1e-3
+    # Same frame as the natal chart: the ascendant from that call matches the engine's.
+    assert abs(ascmc[0] % 360 - body['ascendant']['lon']) < 0.01
+
+
+def test_bhava_chalit_non_mc_house_systems_keep_working_without_birth_moment() -> None:
+    body = _golden_natal_body()
+    for key in ('year', 'month', 'day', 'hour', 'minute', 'second', 'lat', 'lon', 'tz'):
+        body.pop(key)
+    result = _handler()._compute_bhava_chalit({**body, 'house_system': 'equal'})
+    assert result['success'] is True
+    assert [house['span_degrees'] for house in result['result']['boundaries']['houses']] == [30.0] * 12
+
+
 def test_sudarshana_endpoint_returns_three_reference_points() -> None:
     handler = _handler()
     result = handler._compute_sudarshana({