Ability gate

Ask: none | tool-gate | story-flag | both.

Ownership

The gate consumes capability/story state from their true owners. It does not own tutorials, map pins, save storage or rest-site placement.

Contract

Each gate publishes:

• stable gate_id
• required capability IDs and/or story predicate IDs
• predicate version
• open/closed/blocked result
• optional authored feedback/reference IDs

Evaluate the gate from authoritative state. Duplicate unlock notifications are idempotent. A save or patch migration preserves stable capability/story identity rather than keying by localized text or scene index.