RFC: Calling a product worker from its app

Source PR: #468 · docs/rfcs/0027-surface-worker-calls.md · @BigTava

Description

A Worker trait adds call_worker, which invokes a named export of the calling product's own worker with a JSON payload and returns the answer.

Motivation

A product's views and its worker have no protocol between them, so work meant to outlive the view runs in the page and dies with it. Without a bounded call, products will ask to hand the worker a function instead.

Requirements

• The request carries no product id — the Host supplies the caller identity.
• api_name must be an export the verified archive already declared; nothing loads on demand.
• deadline_ms defaults to and is clamped by the Host window.
• Errors are Unavailable | Invalid | Timeout | Crashed | Version, with Unavailable undifferentiated on purpose.
• The worker manifest declares which executables may call it.

Tasks

• RFC document body
• Implementation — rust-core
• Implementation — hosts
  • dotli
  • Desktop
  • iOS
  • Android
  • host-cli

Note: RFC number 0027 is also claimed by #420.

Start with docs/rfcs/0027-surface-worker-calls.md and the source PR #468, then review the requirements and the rust-core and host implementation task list. Confirm how the RFC number conflict with #420 is resolved. Done means the RFC body and the listed rust-core, dotli, Desktop, iOS, Android, and host-cli work are addressed.