Turso Allocator Migration

Use this skill for Turso allocator migration work in core, especially when replacing standard heap collections with crate::alloc aliases or adding fallible allocation paths.

Core Rules

• Use crate::alloc::* in migrated modules.
• Keep call-site names stable: Vec, Box, HashMap, BTreeSet, Arc, and similar standard names.
• Use Turso for new allocator-specific names, not Limbo.
• Use cfg(nightly) for nightly allocator behavior, not Cargo features.
• Do not change set_allocator unless the user explicitly asks.
• Keep Arc and Weak routed through crate::sync for shuttle compatibility for now. Leave allocator-aware shared pointers as a TODO.
• Do not migrate tests to fallible allocation unless they block compilation or the user asks.

Import Pattern

For migrated modules, prefer a single allocator namespace import: