fix(engine): dispositor cycles are not collapsed to one planet; dasa convergence drops uncalibrated probabilities (upstream e9beae6b)

final_dispositor_from_chain and its regression test are upstream
yinduzhanxing e9beae6b; probability is None with probability_basis. The
Narayana convergence additions of that commit are out of scope.
TASK-upstream-sync4-20261002 T7.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N4f2nya58RoRu4yEmJgRGE

scripts/jyotish_engine.py

@@ -472,6 +472,29 @@ def calc_inter_chart_linkage(planet_name, d1_data, d9_data, d10_data, d12_data=N
     return result
 
 
+def final_dispositor_from_chain(chain):
+    """Return a terminal only for a self-loop; retain multi-body cycles.
+
+    Ported from upstream yinduzhanxing e9beae6b (TASK-upstream-sync4-20261002 T7).
+    """
+    path = []
+    for row in chain:
+        planet, target = row.get('planet'), row.get('dispositor')
+        if not planet or not target or (path and path[-1] != planet):
+            return None
+        if not path:
+            path.append(planet)
+        if target == planet:
+            return planet
+        if target in path:
+            cycle = path[path.index(target):]
+            rotations = [cycle[i:] + cycle[:i] for i in range(len(cycle))]
+            cycle = min(rotations)
+            return 'Cycle: ' + ' -> '.join(cycle + cycle[:1])
+        path.append(target)
+    return None  # incomplete or depth-limited chain is not a terminal
+
+
 def calc_all_dispositor_chains(planets_data):
     """为所有行星计算定位星链"""
     result = {}
@@ -15023,21 +15046,20 @@ def _calc_dasa_convergence(dasha_result, chara_dasha_result, yogini_result, plan
         sc = info['system_count']
         if sc >= 4:
             info['convergence_level'] = 'L5'
-            info['probability'] = '85-92%'
             info['interpretation'] = '四个及以上推运系统同时激活，顶级收敛信号'
         elif sc >= 3:
             info['convergence_level'] = 'L4'
-            info['probability'] = '75-85%'
             info['interpretation'] = '三系统同时激活，极强信号'
         elif sc >= 2:
             info['convergence_level'] = 'L3'
-            info['probability'] = '50-65%'
             info['interpretation'] = '双系统激活，强信号'
         else:
             info['convergence_level'] = 'L1'
-            info['probability'] = '+15-20%'
             info['interpretation'] = '单系统激活，需Transit确认'
 
+        info['probability'] = None
+        info['probability_basis'] = 'No empirical probability calibration; level counts activating systems only.'
+
     # 收敛窗口（最高优先级的领域）
     top_domains = sorted(domain_activations.items(), key=lambda x: x[1]['system_count'], reverse=True)[:5]
 
@@ -15725,23 +15747,8 @@ def cmd_full_reading(args):
         report['modules']['inter_chart_linkage'] = ic_result
 
         # 补充：每个行星的"最终定位星"（Dispositor Chain 的最后一个非循环元素）
-        final_dispositors = {}
-        for pname, chain in dc_result.items():
-            if chain:
-                # 找到最后一个不重复的元素
-                seen = set()
-                last_valid = None
-                for item in chain:
-                    if item['dispositor'] in seen:
-                        break
-                    seen.add(item['dispositor'])
-                    last_valid = item
-                if last_valid:
-                    final_dispositors[pname] = last_valid['dispositor']
-                else:
-                    final_dispositors[pname] = chain[-1]['dispositor'] if chain else None
-            else:
-                final_dispositors[pname] = None
+        # A multi-planet cycle has no unique terminal dispositor.
+        final_dispositors = {p: final_dispositor_from_chain(c) for p, c in dc_result.items()}
         report['modules']['final_dispositors'] = final_dispositors
 
     except Exception as e:

tests/test_dispositor_cycle_resolution.py

@@ -0,0 +1,38 @@
+"""Do not collapse a directed dispositor cycle into an arbitrary terminal."""
+import ast
+from pathlib import Path
+
+
+def resolver():
+    # Isolate the pure function without importing the large CLI and adapters.
+    source = Path(__file__).parents[1] / 'scripts/jyotish_engine.py'
+    tree = ast.parse(source.read_text())
+    node = next(n for n in tree.body if isinstance(n, ast.FunctionDef)
+                and n.name == 'final_dispositor_from_chain')
+    namespace = {}
+    exec(compile(ast.Module(body=[node], type_ignores=[]), str(source), 'exec'), namespace)
+    return namespace[node.name]
+
+
+def chain(*names):
+    return [{'planet':a,'dispositor':b} for a,b in zip(names,names[1:])]
+
+
+def test_cycle_rotation_and_leading_planet():
+    f = resolver()
+    expected = 'Cycle: Jupiter -> Mercury -> Jupiter'
+    assert f(chain('Mercury','Jupiter','Mercury')) == expected
+    assert f(chain('Jupiter','Mercury','Jupiter')) == expected
+    assert f(chain('Venus','Jupiter','Mercury','Jupiter')) == expected
+
+
+def test_terminal_and_incomplete_are_distinct():
+    f = resolver()
+    assert f(chain('Sun','Mars','Saturn','Saturn')) == 'Saturn'
+    assert f(chain('Sun','Mars')) is None
+    assert f([]) is None
+    assert f(chain('Sun','Mars') + chain('Venus','Venus')) is None
+
+
+def test_three_body_cycle_preserves_direction():
+    assert resolver()(chain('Sun','Mars','Moon','Sun')) == 'Cycle: Mars -> Moon -> Sun -> Mars'