Pattern
Factory
SymbolFactory picks renderer per id.
Where: src/view/symbols/SymbolFactory.ts.
The rule: given a symbol id, return the right Container
subclass (sprite, animated sprite, Spine). The factory reads per-id config; call
sites are agnostic.
Why: lets you mix sprite and Spine symbols in the same game. Extends cleanly to new renderer types without touching the caller.