Enumeration URSymbolType

Legacy enumeration for symbol kinds used by the original URSymbol abstraction.

DEPRECATION: The symbol system has been replaced with dedicated declaration/reference types and description interfaces found under @universal-robots/contribution-api/types/symbols. Migrate to:

• Variable: VariableDeclaration, VariableReference, VariableDescription
• Function: FunctionDeclaration, FunctionReference, FunctionDescription
• Module: ModuleDeclaration, ModuleReference, ModuleDescription
• Logic program functionality is now exposed through program node metadata rather than a standalone symbol.

This enum remains only for backwards compatibility of existing extensions. Do not use it in new code.