Authority server expects params: SqlValue[] (positional array) but
ST-BME was sending params as a named map with :placeholders, causing
'invalid type: map, expected a sequence' deserialization errors.
Added convertNamedParamsToPositional() in AuthoritySqlHttpClient that
transforms :name placeholders to ? and extracts values in order before
sending to the server. This fixes the SQL probe failure that kept the
graph stuck in LOADING state.