Add protocol HTTP application boundary.

[samuel-williams-shopify]

Summary

• Add Utopia::Application as a protocol-facing boundary that wraps Protocol::HTTP::Request into Utopia::Request and normalizes responses.
• Add lightweight Utopia::Request and Utopia::Response helpers.
• Rewrite Utopia middleware around protocol HTTP requests and responses.
• Parse query and form data with the released protocol-url and protocol-multipart parsers, including configurable endpoint limits and streamed uploads.
• Stream static responses with Protocol::HTTP::Body::File and resolve byte ranges with Protocol::HTTP::Header::Range.
• Use Protocol::HTTP::Status for standard status descriptions and remove the obsolete Rack-body interface from Utopia::HTTP::Status.

Follow-up

• Add request-level parser dispatch for additional structured body formats where needed.
• Define and validate the complete set of supported session cookie options.
• Define duplicate and malformed request-cookie handling explicitly.

Tests

• bundle exec sus
• 292 tests, 702 assertions.
• Decode coverage: 497/497 public definitions.