serviceability: accesspass + resource instruction builders (Rust)

[juan-malbeclabs]

Part of #4014.

Add src/accesspass.rs and src/resource.rs builders. Resource args carry data-bearing enums (ResourceType, IdOrIp) — cover their borsh encoding explicitly.

Acceptance

• One pure builder per non-deprecated accesspass/resource instruction.
• Golden fixtures exercise the data-bearing enum encodings.
• Unit tests + ix_* golden fixtures.

[juan-malbeclabs]

Closing for now — this work is captured in RFC-26 (rfcs/rfc26-rust-instruction-builder-library.md). Will reopen once the RFC is approved.

[juan-malbeclabs]

Reopening: RFC-26 was merged (#4035). Reviewed this issue against the final RFC — scope and design decisions are still aligned. The implementation work tracked here is still pending.