Module cancellation 

Streaming cancellation registry.

This module centralizes cancellation-token storage semantics for streaming requests. Frontends (GUI/CLI) are responsible for choosing an appropriate cancel key that prevents cross-window or cross-session leakage. The core owns:

• token storage
• collision semantics (replacing an existing token cancels the old one)
• cancellation (remove + cancel)

Structs

StreamCancellationRegistry

In-memory registry of streaming cancellation tokens.

Statics

STREAM_CANCELLATIONS

Global cancellation registry used by frontends that need process-wide cancellation.