feat(upstream): merge a6f47abd engine, MCP, and orchestrator

Three-way-merge calculation modules and pl9-export into the product fork while keeping commercial API routes, Raman ayanamsa, and the consultation contract as a keypath superset.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/domain_calculation_service.py

@@ -16,7 +16,9 @@ from ayanamsa_utils import (
     DEFAULT_AYANAMSA_NAME,
     UnsupportedAyanamsaError,
     apply_ayanamsa,
+    is_supported_ayanamsa_name,
     normalize_ayanamsa_name,
+    supported_ayanamsa_names,
 )
 from dasha_analyzer import build_dasha_timeline, lon_to_nakshatra
 from jyotish_engine import SIGNS, compute_chart_data
@@ -285,6 +287,10 @@ def compute_transit_longitude(
         local_dt = datetime.strptime(reference_date[:10], "%Y-%m-%d").replace(hour=12)
     except (TypeError, ValueError) as exc:
         raise CalculationError("reference_date must be YYYY-MM-DD") from exc
+    if not is_supported_ayanamsa_name(ayanamsa):
+        raise CalculationError(
+            f"unsupported ayanamsa: {ayanamsa!r}. Supported values: {', '.join(supported_ayanamsa_names())}"
+        )
     ayanamsa_name = normalize_ayanamsa_name(ayanamsa)
     with _SWISSEPH_LOCK:
         apply_ayanamsa(ayanamsa_name, swe)