feat: add nowcast point alarm update client with dry-run

Patches registrations from CSV rows, sending only non-blank cells, validating lat/lng pairing and ranges locally, warning about the speedThreshold PATCH gap (GAIA-476) and recording status, httpStatus and errorBody back into the CSV.

tests/test_point_alarm.py

@@ -15,6 +15,8 @@ from common import ApiError, ConfigurationError
 from common.client import ApiResponse
 from point_alarm import (
     PointRegistrationProcessor,
+    PointUpdateProcessor,
+    build_update_payload,
     PointStore,
     fetch_pages,
     flatten_registration,
@@ -243,5 +245,54 @@ class RegisterTest(unittest.TestCase):
         self.assertEqual(rows[0]["status"], "FAILED")
 
 
+class UpdateTest(unittest.TestCase):
+    def test_payload_skips_blank_cells(self) -> None:
+        payload = build_update_payload(
+            {"registrationId": REG_ID, "lat": "39.9", "lng": "32.8", "radius": "",
+             "severityThreshold": "high", "precipitationIntensities": "light|heavy"}
+        )
+        self.assertEqual(payload["boundary"], {"point": {"lat": 39.9, "lng": 32.8}})
+        self.assertEqual(payload["filter"]["thunderstorm"], {"severityThreshold": "HIGH"})
+        self.assertEqual(payload["filter"]["precipitation"]["intensities"], ["LIGHT", "HEAVY"])
+
+    def test_payload_errors(self) -> None:
+        for row in (
+            {"registrationId": REG_ID},
+            {"registrationId": REG_ID, "lat": "39"},
+            {"registrationId": "x", "radius": "5"},
+            {"registrationId": REG_ID, "radius": "60000"},
+            {"registrationId": REG_ID, "lightningType": "BAD"},
+        ):
+            with self.assertRaises(ConfigurationError, msg=row):
+                build_update_payload(row)
+
+    def test_dry_run_does_not_call_or_write(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            path = Path(tmp) / "u.csv"
+            text = f"registrationId;radius\n{REG_ID};500\n"
+            path.write_text(text, encoding="utf-8")
+
+            class Boom:
+                def update(self, *_):
+                    raise AssertionError("must not be called")
+
+            PointUpdateProcessor(Boom(), csv_path=path, dry_run=True).run()
+            self.assertEqual(path.read_text(encoding="utf-8"), text)
+
+    def test_update_records_result(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            path = Path(tmp) / "u.csv"
+            path.write_text(f"registrationId;radius\n{REG_ID};500\n", encoding="utf-8")
+
+            class Svc:
+                def update(self, payload, key):
+                    return ApiResponse(200, {})
+
+            PointUpdateProcessor(Svc(), csv_path=path).run()
+            with path.open(encoding="utf-8-sig", newline="") as handle:
+                row = next(csv.DictReader(handle, delimiter=";"))
+            self.assertEqual((row["status"], row["httpStatus"]), ("SUCCESS", "HTTP_200"))
+
+
 if __name__ == "__main__":
     unittest.main()