v1.4.0

[1.4.0] - 2026-06-23

• Drop the activesupport lower-bound; constraint is now < 9.0 (was ~> 7.1.6).
• Prevent ErrorResponse::RequestError from being swallowed by broad handlers such as rescue_from Exception.
• Handle RequestError through ErrorResponse::Helper#rescue_with_handler before falling back to generic rescue flow.
• Add RSpec coverage for rescue order behavior with both RequestError and non-RequestError exceptions.
• Update README to document the rescue order guarantee and usage notes with broad exception handlers.
• Released as minor bump (1.4.0) so downstream services pinned to ~> 1.3 or earlier are not auto-updated; upgrade to ~> 1.4 is opt-in per service.