Skill: Motoko mo:base → mo:core Migration

AI Quick Checklist (Do Not Skip)

1. Versions

• Ensure dfx 0.31+
• Confirm repo compiles before starting
• In mops.toml add core = "2.2.0"
• update moc in mops.toml to "1.3.0" in [toolchain] and [requirements] sections.
• if wasmtime is present in mops.toml, upgrade it to at least "42.0.1"
• Do NOT remove base dependency until Phase 5 is completed

2. dfx.json Flags (per canister)

• wasm_memory_persistence: keep

3. Mechanical Renames (Phases 1–2)

• Imports: mo:base/* → mo:core/* (with noted exceptions)
• Types-only: Prefer mo:core/Types for type-only imports (e.g., Iter.Iter → Types.Iter, Result.Result<T,E> → Types.Result<T,E>)
• Style: If importing ≤2 types from mo:core/Types, prefer named type imports (e.g., import { type Result; type Iter } "mo:core/Types";) and then use Result<T> / Iter<T> in code; if importing ≥3 types, import the whole module (import Types "mo:core/Types";).