Release v4.238.0

Part of #1012.

Changed

• A feature and a module body accept toolbar <name> with the same item / button lines as a screen toolbar. The entries are the feature's own buttons for the toolbar slot of the screens beneath it, each linked to a command of the feature (item <id> action <Command>) or to a State Change slice (button).
• confirm "<text>" (or a $strings. token) on a toolbar item and on a button: the question the user answers before the command runs or the dialog opens.
• C# and TypeScript compilers, printer (round trip), syntax walker, folder merge, syntax JSON/schema (members omitted when empty, so existing documents keep their bytes), contract golden, grammar.md, screens.md, diagnostics.md.
• New diagnostic PLAY0808 (warning): a feature/module toolbar item links a command no slice of the feature declares.
• New conformance vector feature-toolbars (TypeScript golden agrees with C#).

Fixed

• A toolbar could not be declared on a feature or a module (PLAY0024); the same buttons had to be copied into every screen.
• A toolbar item could not carry a confirmation (PLAY0103).

AI corpus: Cratis/AI#846