test(dasha): keep the upstream boundary contract (upstream 07fc5be3)

A8 is tests only. dasha_analyzer.py is frozen and was not edited. Both contract tests passed.

Co-Authored-By: Grok (agent loop)

tests/test_upstream_sync9_dasha_analyzer_boundary_contract.py

@@ -0,0 +1,23 @@
+"""Dasha analyzer must use the common left-closed Nakshatra partition."""
+
+from fractions import Fraction
+import math
+
+from scripts.dasha_analyzer import NAKSHATRA_LIST, lon_to_nakshatra
+
+
+def test_exact_star_starts_select_the_new_star_with_zero_progress():
+    for index in range(27):
+        longitude = float(Fraction(40 * index, 3))
+        nakshatra, progress, pada = lon_to_nakshatra(longitude)
+        assert nakshatra == NAKSHATRA_LIST[index]
+        assert progress == 0.0
+        assert pada == 1
+
+
+def test_immediate_preceding_float_stays_in_the_prior_star():
+    boundary = float(Fraction(40 * 7, 3))
+    nakshatra, progress, pada = lon_to_nakshatra(math.nextafter(boundary, -math.inf))
+    assert nakshatra == NAKSHATRA_LIST[6]
+    assert 0.999999 < progress < 1.0
+    assert pada == 4