ADDED Requirements

Requirement: Pack validation SHALL distinguish unknown rule words from unsupported mechanics

The loader SHALL accept optional manifest.features as a list of unique supported feature identifiers and SHALL reject unknown required features before registration with an upgrade message. A level SHALL reject an object noun equal to a custom property implemented by that level. A word SHALL count as a known noun when it is placed or named as an automaton subject in that proof, or listed in the pack's palette or vocabulary. Other words that are neither core words nor implemented properties in that proof SHALL receive a nonfatal note with word and proof context, whether or not they currently complete a sentence. A word declared as a property in one proof and used as an object noun in another SHALL receive an ambiguity note even if it is in the pack palette or vocabulary. Existing packs with automata and no feature list SHALL remain valid.

Scenario: Unknown predicate receives a note

• WHEN a proof contains DOOR IS SHUT with SHUT absent from that proof's implemented properties and nouns
• THEN local preview succeeds, reports a note identifying SHUT, the proof, and the noun-transform consequence, without blocking installation

Scenario: Loose unknown word receives a note

• WHEN a proof places a loose SHUT word that can be moved into a sentence but declares no SHUT behavior or noun in that proof
• THEN preview reports a note for SHUT even before the sentence is formed

Scenario: Known noun transformation remains valid

• WHEN a proof contains ROCK IS MIAU and places a MIAU object in that proof
• THEN no unknown-word note is returned for MIAU

Scenario: Pack-defined transformation target is known

• WHEN one proof contains ROCK IS GEM, the pack palette or vocabulary defines GEM, and no GEM object starts in that proof
• THEN no unknown-word note is returned for GEM

Scenario: Pack-wide property and thing ambiguity receives a note

• WHEN one proof declares SHUT as a custom property and another proof uses SHUT as an object noun and places its word
• THEN preview reports a nonfatal ambiguity note for SHUT even if the pack palette or vocabulary names it

Scenario: Declared automaton property remains semantic

• WHEN a level declares TICK through automata[].property and contains MOUSE IS TICK
• THEN no unknown-predicate warning is returned for TICK

Scenario: Property declared only in another proof receives a note

• WHEN one proof declares TICK through automata and another proof contains CLOCK IS TICK without a TICK automaton
• THEN the second proof reports that TICK has no property behavior there unless the pack defines TICK as a noun

Scenario: Property noun collision is rejected

• WHEN a level declares TICK as an automaton property and places an object whose noun is TICK
• THEN the loader rejects the level with the object's path and does not register part of the pack

Scenario: Unsupported feature is rejected

• WHEN a pack declares manifest.features: ['pairs'] in a host that supports only automata
• THEN the loader rejects the pack with a readable newer-version message before any level is installed

Scenario: Legacy automata pack remains usable

• WHEN a valid existing pack contains automata but omits manifest.features
• THEN the current loader accepts it and preserves its automata behavior