Request-local HTTP/1 response and proxy CONNECT header budgets.
Pass response_header_limits: [...] to HTTP.fetch/2. Supported positive
integer limits are :max_head_bytes (65,540), :max_field_bytes (65,536),
:max_fields (32,768), :max_connect_head_bytes (16,384),
:max_informational_responses (16) and :max_informational_bytes (1,048,576).
Head bytes include the status line and terminating CRLFs; field bytes include
the field name, colon and value, excluding CRLF. Body bytes are not charged.
Informational counts and bytes accumulate until the final response.
Failures are {:response_header_limit, %{stage: :response | :connect, limit: atom, maximum: integer, observed: integer}}. No header values appear
in this evidence. Callers omitting the option retain the legacy head-limit
errors; informational responses still have finite default budgets.