fix(tithi): use the source lord order (BUG-1473, upstream 33537b31)

Tithi lords follow tithi_seed. No new scripts/tithi_ashtottari.py. Upstream source tests passed.

Co-Authored-By: Grok (agent loop)

scripts/tithi_lord.py

@@ -8,6 +8,14 @@ Tithi（月日）是月亮与太阳的黄经差除以12°，共30个 Tithi（阴
 
 import math
 
+if __package__:
+    from .research_timing.cycles import tithi_seed
+else:
+    try:
+        from research_timing.cycles import tithi_seed
+    except ImportError:
+        from scripts.research_timing.cycles import tithi_seed
+
 # Tithi 名称（1-15 Shukla 盈，1-15 Krishna 亏）
 TITHI_NAMES = {
     1: "Pratipad (1)", 2: "Dvitiya (2)", 3: "Tritiya (3)", 4: "Chaturthi (4)",
@@ -16,15 +24,12 @@ TITHI_NAMES = {
     13: "Trayodashi (13)", 14: "Chaturdashi (14)", 15: "Purnima/Amavasya (15)",
 }
 
-# Tithi 守护星（Parashara 系统）
-# 1=Sun, 2=Moon, 3=Mars, 4=Mercury, 5=Jupiter, 6=Venus, 7=Saturn
-# Tithi 1-7: Sun, Moon, Mars, Mercury, Jupiter, Venus, Saturn
-# Tithi 8-14: Sun, Moon, Mars, Mercury, Jupiter, Venus, Saturn
-# Tithi 15 (Purnima/Amavasya): Sun
+# PVR Integrated Approach table 3: Shukla mapping. Krishna 15 is Rahu,
+# not Saturn; get_tithi_lord shares the existing thirty-day tithi_seed rule.
 TITHI_LORD_MAP = {
     1: 0, 2: 1, 3: 2, 4: 3, 5: 4, 6: 5, 7: 6,
-    8: 0, 9: 1, 10: 2, 11: 3, 12: 4, 13: 5, 14: 6,
-    15: 0,
+    8: 7, 9: 0, 10: 1, 11: 2, 12: 3, 13: 4, 14: 5,
+    15: 6,
 }
 
 # 逆映射：行星索引 → 名称
@@ -62,11 +67,14 @@ def calc_tithi(sun_deg, moon_deg):
 def get_tithi_lord(tithi_num, paksha):
     """
     获取 Tithi 的守护星。
-    Tithi 1-15 的守护星在阴阳月中是一样的（Parashara 系统）。
+    PVR table 3；满月土星，新月罗睺，其余阴阳月对应一致。
     """
-    # Tithi 1-15 的守护星（阴阳月相同）
-    lord_idx = TITHI_LORD_MAP[tithi_num]
-    return lord_idx, PLANET_NAMES[lord_idx]
+    if type(tithi_num) is not int or not 1 <= tithi_num <= 15:
+        raise ValueError('tithi_num must be integer 1..15 within the paksha')
+    if paksha not in ('Shukla', 'Krishna'):
+        raise ValueError('paksha must be Shukla or Krishna')
+    name = tithi_seed(tithi_num + (15 if paksha == 'Krishna' else 0))
+    return PLANET_NAMES.index(name), name
 
 
 def calc_tithi_lord_full(sun_deg, moon_deg, planets=None, houses=None):
@@ -122,6 +130,8 @@ def calc_tithi_lord_full(sun_deg, moon_deg, planets=None, houses=None):
         15: 'Purnima（满月/新月，能量极点）',
     }
     special_note = special_tithis.get(tithi_num)
+    if tithi_num == 15:
+        special_note = 'Purnima（满月）' if paksha == 'Shukla' else 'Amavasya（新月）'
 
     # Tithi 适忌活动表（完整版）
     tithi_activities = _get_tithi_activities(tithi_num, paksha)
@@ -140,6 +150,7 @@ def calc_tithi_lord_full(sun_deg, moon_deg, planets=None, houses=None):
         "tithi_deg_in": round(tithi_deg, 2),
         "tithi_lord_idx": lord_idx,
         "tithi_lord_name": lord_name,
+        "tithi_lord_source": "PVR Integrated Approach table 3, file page 24; shared thirty-tithi ruler table",
         "raw_diff_deg": round(raw_diff, 2),
         # v7.0 新增
         "tithi_class": tithi_class,
@@ -181,6 +192,7 @@ def calc_tithi_lord_full(sun_deg, moon_deg, planets=None, houses=None):
             4: "Tithi Lord 为木星：智慧、导师、扩张、幸运。木星强则有人生指引。",
             5: "Tithi Lord 为金星：享乐、艺术、关系、舒适。金星强则生活有质量。",
             6: "Tithi Lord 为土星：纪律、延迟、责任、苦行。土星强则能承受压力。",
+            7: "Tithi Lord 为罗睺（PVR Table 3）；应结合罗睺的本命位置与关联星综合判断。",
         }
         result["tithi_lord_interpretation"] = interpretations.get(lord_idx, "")
 

tests/test_upstream_sync9_tithi_lord_source.py

@@ -0,0 +1,34 @@
+import pytest
+
+from scripts.tithi_lord import calc_tithi_lord_full, get_tithi_lord
+
+
+# PVR table 3, file p24. Independent explicit source expectation.
+EXPECTED = ('Sun Moon Mars Mercury Jupiter Venus Saturn Rahu Sun Moon Mars Mercury Jupiter Venus Saturn '
+            'Sun Moon Mars Mercury Jupiter Venus Saturn Rahu Sun Moon Mars Mercury Jupiter Venus Rahu').split()
+
+
+@pytest.mark.parametrize('number,lord',list(enumerate(EXPECTED,1)))
+def test_all_thirty_report_rulers_and_angular_boundaries(number,lord):
+    at_start=calc_tithi_lord_full(0,(number-1)*12)
+    just_before_end=calc_tithi_lord_full(0,number*12-1e-7)
+    for result in (at_start,just_before_end):
+        assert result['tithi_absolute']==number
+        assert result['tithi_lord_name']==lord
+
+
+def test_new_and_full_moon_differ_and_chart_link_follows_correct_lord():
+    full=calc_tithi_lord_full(0,174)
+    new=calc_tithi_lord_full(0,354,{'Rahu':{'sign':'Taurus','house':2}}, {})
+    assert full['tithi_lord_name']=='Saturn'
+    assert new['tithi_lord_name']=='Rahu'
+    assert full['special_note'] != new['special_note']
+    assert new['tithi_lord_sign']=='Taurus'
+    assert new['tithi_lord_house']==2
+    assert new['tithi_lord_interpretation']
+    assert calc_tithi_lord_full(0,360)['tithi_absolute']==1
+
+
+@pytest.mark.parametrize('number,paksha',[(True,'Shukla'),(0,'Shukla'),(16,'Krishna'),(1,'unknown')])
+def test_invalid_seed_is_not_silently_accepted(number,paksha):
+    with pytest.raises(ValueError):get_tithi_lord(number,paksha)