feat: add nowcast point alarm page client with SQLite store

Adds point_alarm.py (flattening, secret masking, SQLite upsert store, paged fetch with 403 fallback, CSV/TXT export, shared filter loader), nowcast-point-page.py CLI and unit tests. Register will read the shared filter from nowcast-point-alarm-filter.json instead of repeating it in the CSV.

geo_alarm.py

@@ -18,6 +18,7 @@ from nowcast_common import (
     read_json_object,
     response_warnings,
     as_uuid,
+    fetch_account_id,
     load_webhook_config,
     write_csv_atomic,
 )
@@ -86,13 +87,7 @@ class GeoAlarmService:
         self.client = client
 
     def get_account_id(self) -> str:
-        response = self.client.request_json("GET", "/v1/users/me")
-        data = response.data
-        account = data.get("account") if isinstance(data, dict) else None
-        account_id = account.get("id") if isinstance(account, dict) else None
-        if not as_uuid(account_id):
-            raise ApiError("/v1/users/me yanıtında geçerli account.id bulunamadı.")
-        return account_id
+        return fetch_account_id(self.client)
 
     def list_cities(self) -> list[dict[str, Any]]:
         data = self.client.request_json(