Harden prashna production entrypoints

tests/test_prashna_context.py

@@ -0,0 +1,32 @@
+from datetime import datetime
+
+import pytest
+
+from scripts.prashna_context import PrashnaContextError, build_prashna_context
+
+
+def test_prashna_context_uses_backend_chart_from_question_moment():
+    packet = build_prashna_context({
+        "question_text": "Will this proceed?",
+        "question_timestamp": "2026-07-12T12:00:00+08:00",
+        "lat": 39.9042,
+        "lon": 116.4074,
+        "timezone": 8,
+        "ayanamsa": "lahiri",
+        "node_mode": "mean",
+        "location_convention": "wgs84",
+    })
+
+    assert packet["status"] == "computed"
+    assert packet["chart_source"] == "swiss_ephemeris_backend"
+    assert packet["ascendant"]["degree"] >= 0
+    assert "Sun" in packet["planets"]
+    assert "question_timestamp" in packet
+
+
+def test_prashna_context_rejects_missing_time_or_non_wgs84_location():
+    base = {"question_text": "x", "lat": 1, "lon": 1, "timezone": 0}
+    with pytest.raises(PrashnaContextError, match="question_timestamp"):
+        build_prashna_context(base)
+    with pytest.raises(PrashnaContextError, match="location_convention"):
+        build_prashna_context({**base, "question_timestamp": "2026-01-01T00:00:00+00:00", "location_convention": "unknown"})