Shared helper now reads several feature gates, including new tengu_snappy_tower

What

A feature gate is a switch Anthropic's servers can use to turn a feature on or off. A new block of code now reads several of them in one place, instead of each reader carrying its own name.

• It covers tengu_tingly_pearl, tengu_foamy_heron, tengu_vast_puddle and tengu_snappy_tower. The last one is new, and nothing calls its reader in this change, so what it controls is unknown.
• Each check counts as off only when the server's value is explicitly false and also comes from a non-default host. A missing value, a missing reader or an error counts as on. tengu_tingly_pearl and tengu_foamy_heron also have a built-in fallback of true.
• The same block adds a "reading" mode for the shell command parser with the values "refuse", "rule off" and "as bash reads it".
• A nearby constant that used to hold a file path now holds the gate name tengu_nested_ripple. What reads it and its default were not traced.

Nothing has been read yet about any of these gates.

Why

The code is written so these features run unless the server explicitly turns them off. The new reading mode suggests a link to how shell commands are parsed for permission checks, though what each gate does was not resolved.